Once upon a time

Finals, second to last day - 

Today, I may have failed a final for the first time in college. This has been a semester of firsts, I guess. Funny - I know I may have just failed ecology, but somehow, I know the world is still going to move on, and I feel like I've bee given a big new piece of opportunity. 

I smell like finals.

erg.

( :

A good song, or, Give me this Mountain

He Said Love, by Barclay James Harvest. Listen to it! 

Well, friends, here I am, a day and half into finals week, preparing to take my geology final at 3:00 p.m., and coming to face to face with my most debilitating weaknesses. (Namely, spinning my wheels, staying up way too late, nervous eating, feeling sorry for myself about boys, angsting about the universe, etc. Good thing I don't back down easy. And good thing I'm going to see Brad at 11:00. And I have Karate tonight (it's very therapeutic to hit things). Good thing my family loves me no matter what my grades are.

And good thing I can totally do this. I have a week in which to not worry about anything except for loving other people and rocking these finals hardcore. Both of which (with a little help) I am eminently capable of doing. So, as Brad would say, here's to the "Scarlett O'Hara complex"; I'll worry about that tomorrow.

Today, I am present. And I am not afraid.

Good luck to all of you (not that anyone reads this, haha ( :  ) in whatever you may face this week. Give me this mountain!

Jessie

hm

Sometimes I wish I was spanish. Yup.

my pdbio essay

Jessie Riddle

PDBio 120 Dr. Jerry Johnson

November 2009

Are Humans Distance Runners by Nature?

The New York Times published an article on October 27, 2009, discussing the claim that early human beings evolved into distance runners.  The theory known as “persistence hunting” suggests human evolution favored traits that allowed populations to obtain protein by chasing their prey to exhaustion and death. The article references a recent study done at the University of Utah, which points to many human traits that may have evolved in support of persistence hunting. The article also discusses the book recently published entitled Born to Run, which claims that mankind did, indeed, evolve into expert long distance runners, and that the reason running causes so many athletes injury today is our faulty methods of training (including high-tech shoes that detract from the natural use of the feet).

After a careful analysis of this news article, I have concluded that is technically accurate, and relatively specific in the evidences it cites from recent studies. The author did an excellent job of gathering research from multiple sources. However, I also found that the article fails to mention some of the more contradictory elements of the “Persistence Hunting” theory, and so paints a somewhat inaccurate picture of its probable validity. 

Section One

            According to a 2007 study authored by Dr. Daniel Lieberman and Dennis K. Bramble, and published in the journal Sports Medicine, human beings are remarkably well adapted to running long distances. Other recent studies have declared it likely that many modern human phenotypes involved in running are due to our early ancestors “Persistence Hunting.” Scientists from the fields of evolutionary biology, anthropology, neurophysiology, genetic morphology, sports medicine and others are currently debating whether or not Persistence Hunting could have caused the evolution of long distance running capabilities in humans.

This question comes at an important time – the list of medical problems resulting from a sedentary lifestyle is growing alongside the increasing number of exercise-related injuries. New discoveries suggesting if and how humans have evolved towards distance running could provide key insights into helping humans understand the needs and capabilities of their own bodies.  

Section Two

            Dr. Lieberman and Dr. Bramble’s paper describes the current theories on the origin of endurance running, which is referred to as “ER.” They state that the main difficulties of ER stem from three things: energy production and use, stabilizing the body, and regulating the body’s temperature. These three concepts are referred to as energetics, stabilization, and thermoregulation. Lieberman and Bramble account for the way in which humans have dealt with these barriers through the theory that the use of “Persistence Hunting” led to natural selection for traits that augmented ER abilities. They define Persistence Hunting as a pre-weapon technique beginning between 1.5 and 2 million years ago that involves chasing prey through the intense heat over long periods of time and killing the exhausted animal by hand.

Section Three

            Energetics

The first issue discussed by Lieberman and Bramble is energetics. They explain that humans absorb the shock from the ground involved in running through tendons in the legs, converting potential energy to kinetic energy through a “mass-spring gait.” This means that the body’s Center of Mass falls after a running step is taken, pushing “elastic” energy into the tendons of the leg to be released through the leg’s upward motion.  All ‘cursorial’ (walking) animals use the mass-spring gait to run. In walking there is no aerial phase and the legs have a higher friction with the ground, but running (due to its aerial phase) requires more kinetic energy to sustain, and so despite it’s minimal contact with the ground, it comes at a higher metabolic cost[i]

According to a 2009 study in the Journal of Human Evolution, humans, like other cursorial animals, minimize the costs of both running and walking at certain speeds. The study also states that running slowly is the least energetically efficient pace for humans[ii]. However, Bramble and Lieberman write that humans are remarkably well-adapted for prolonged usage of the mass-spring gait, due to “numerous tendons [in the legs], such as the Achilles…which are absent or tiny in other African Apes,” and “spring-like ligaments” in the feet.  These studies appear to conflict, because one suggests that slow running is inefficient, and the other suggests that humans have evolved musculature over time specifically suited to long periods of running. This conflict may be resolved through further research on a specific type of Persistence Hunting referenced in the 2009 study, which involves extended periods of a running at a relatively faster pace alternated with periods of walking. This would allow for continued effort over long time periods and still allow humans to cover great distances

            Stability

            Bramble and Lieberman state that running presents more problems in terms of stability than walking. Thus, in a situation where humans are required to run for long distances, traits would likely become dominant that aid in stabilization while running. The authors suggest that this is, indeed, what humans have, in several key muscle groups. These include a narrow waist, a mobile thorax (the area from the sternum to the diaphragm) that is separated from the neck and thus allows the arms and trunk to rotate separately, sensory reflexes (specifically, the ones that allow us to absorb information and stay upright) that are suited to the rapid movements generated by running , and the gluteus maximus.

The gluteus maximus is frequently mentioned in studies concerning Persistence Hunting, because it has a markedly different structure in humans than in chimpanzees. In 2006, Lieberman, Bramble and several other scientists did a study determining the utilization of the gluteus maximus in running versus walking. They determined that this muscle’s much larger upper portion and lack of a lower portion is “unique to hominids.[iii]” Several theories could account for the divergence of this muscle for Homo sapiens, such as digging or climbing, but it clearly stabilizes the trunk and would thus have been very beneficial in ER (and thus Persistence Hunting). The lack of another human function that so significantly utilizes the gluteus maximus makes it seem likely that ER contributed to genetic selection for this muscle. 

            Thermoregulation

            Lieberman and Bramble describe thermoregulation as the most significant physiological challenge in ER.  The amount of muscle activity involved in running produces significantly more heat than walking, which creates a problem for persistence hunters, because Persistence Hunting must take place in a hot environment[iv]. However, modern persistent hunters in desert areas such as Botswana successfully outrun animals that cannot maintain speed in the heat.[v]. According to Lieberman and Bramble, this is due to humans’ use of evapo-transpiration instead of panting.

A Current Anthropology article published in 1984 explains that although panting is initially a better heat conductor than sweating, it limits an animal’s speed, because heat conduction is dependent on oxygen consumption through respiration. This article also points out that “No other species is known to sweat as much per unit surface area as man,” due to the structure and high density of sweat glands and the lack of hair[vi]. This extreme level of sweat secretion would thus enable a hairless, running human to dissipate extreme heat where other animals could not.

This article also states that further research must be done on large mammals to determine whether or not humans’ thermoregulation is unique and if it is related to bipedal ER. However, selection for such a trait suggests a lifestyle and environment that would cause early humans to benefit from high thermoregulation while running.

Section 4

            Through an examination of mechanisms that assist in ER and or Persistence Hunting, there appears to be a compelling case for natural selection of Homo sapiens through such a mechanism. Many of the mechanisms supporting this theory need further exploration. Specific areas in which the debate among scientists or the lack of data clearly necessitate further study include energy use ratios at specific speeds for humans, thermoregulation capacities and mechanisms in large animals other than humans, and the different methods of Persistence Hunting. The work that has been done is ultimately inconclusive. .However, Persistence Hunting continues to gain support as a mechanism for the evolution of endurance running as the details surrounding its origin and role in human evolution become clear.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

News:

Parker-Pope, T. (2009) “The human body is built for distance.” New York Times Web. October 26, 2009

http://www.nytimes.com/2009/10/27/health/27well.html

 

Primary:

Lieberman, D.E. Bramble, D.M. (2007) The evolution of marathon running; capabilities in humans. Sports Medicine 37 (4-5), 288-290

 

Review:

Steudel, K. (1996) Limb Morphology, bipedal gait, and the energetics of human locomotion. American Journal of Physical Anthropology 99 (2), 345-355

 

 

Allied:

 

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[i] Steudel, K. (1996) Limb Morphology, bipedal gait, and the energetics of human locomotion. American Journal of Physical Anthropology 99 (2), 345-355

 

 

[ii] Steudel-Numbers, K.L., Wall-Scheffler, C.M. (2009) Optimal running speed and the evolution of hominin hunting strategies. Journal of Human Evolution 56, 355-360

 

[iii] Lieberman, D.E., et al. (2006) The human gluteus maximus and its role in running. The Journal of Experimental Biology 209, 2143-2155.

 

[iv] Carrier, D.R. et al. (1984) The energetic pardox of human running and hominid evolution. Current Anthropology, 25 (4), 483-495

 

[v] Liebenberg, L. (2006).  Persistence hunting by modern hunter-gatherers. Current Anthropology 47 (6),  017-1025

 

[vi] see iv

 

my ecology essay

 

 

 

 

 

 

Jessie Riddle

Limnoperna fortunei in the Americas

 

 

 

 

 

 

 

 

 

INTRODUCTION

            In 1993, the first specimens of Limnoperna fortunei in South America were discovered in the La Plata River basin of Argentina (Pastorino & Darrigan, 1993, ref. in Darrigan, 2000).  This bivalve mussel species, originally from Southeast Asia, was released into the Río de la Plata estuary through the ballast water of ships (ref. Boltovskoy , Correa, Cataldo, & Sylvester, 2006). L. fortunei quickly expanded beyond the La Plata estuary into other inland waterways, proving remarkably successful in the South American aquatic environment. By the late 1990s, it was observed to be advancing along waterways at a speed of roughly 240 km/yr (Darrigan, 2000).  

The impacts of this “Golden Mussel” have included a decline in some native species and “biofouling,” or an accumulation of organic material that corrodes the affected surface, of the local environment (Darrigan, 2002). Commercial, industrial, and public water supplies in South America have been affected, and L. fortunei is now classified as an invasive species (U.S.A.C.E.). According to the National Invasive Species Council, an invasive species is defined as “a species that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health (I.S.A.C. 2006).” L. fortunei’s invasive behavior, however, may have had some positive impacts, including an increase in benthic (the bottom of an aquatic eco-system) density and a dramatic upswing in local fish harvesting.

L. fortunei’s impact on people and the environment and its invasive qualities have been compared to that of the Zebra mussel, a non-native bivalve species that has caused serious economic and ecological damage in North America (Karatayev, 2007). Although L. fortunei’s ultimate influence may or may not be analogous to that of the Zebra mussel, it appears that both mussels follow similar patterns of reproduction and invasion. It also seems likely that unless checked, L. fortunei will reach North America. L.Fortunei’s remarkable success in South America, coupled with its similarities to the Zebra mussel’s development, has caused speculation that it could supersede the Zebra mussel as an ecological hazard in North American waters.

PURPOSE

            This paper will discuss the impacts of L. fortunei on South American aquatic ecosystems and local industries. It will also discuss the potential impact of an invasion into North America, and the most beneficial courses of action for affected areas. In order to evaluate the situation, this paper will first examine L. fortunei’s rapid progression through South America. It will then document the observed economic and environmental impacts of colonization and biofouling, including an increase in benthic densities, the growth or death of native species, and the corrosion, obstruction and pollution of waterways. Finally, this paper will review the likelihood of an invasion of L. fortunei into North America, and what steps can or should be taken to halt its advance in the Americas.

OBJECTIVE

            It is the author’s opinion that L. fortunei would be very difficult to remove from the locations it has already colonized in South America. The documented impacts of this species do not appear to warrant the effort and expense a complete removal would require. However, they do appear to warrant quick and comprehensive efforts to stop the invasion of new areas. While L. fortunei has increased the numbers of certain freshwater fish, expanded benthic densities and had other positive influences, the observed negative outcomes appear to outweigh the potentially positive results of introduction. The negative consequences of observed invasions have included biofouling of important waterways, pollution of or damage to industrial and commercial water resources, and a loss of native species (thus a loss in overall biodiversity). Specific actions to stop the spread of L. fortunei could include stricter regulations on cleaning and inspection of boat traffic, in addition to the removal of any specimens discovered.

DISCUSSION

The spread of L. fortunei           

L. fortunei was first observed in the Río de la Plata estuary in 1991. It has since colonized South American waterways to a surprising degree, and can now be found in five countries - Brazil, Paraguay, Uruguay, Bolivia and Argentina (Boltovsky 2006.) In 1995, four years after the species was first discovered, population densities in the original site of contact were about 150,000 individuals m² (Darrigan & Ezcurra de Drago, 2000). In 2004, thirteen years after its invasion, many places in the Paraná river delta (at the head of the Río de la Plata estuary) had consistent population densities of 200,000 individuals m² (Sylvester, Dorado, Boltovskoy, Juárez, & Cataldo, 2005). L. fortunei reached Brazil through the Jacuí canal soon after the year 2000. Current populations in this area, about eight years later, are at an average of 118,00 individuals m²(Bergonci, 2009). The fact that the populations in the Jacuí canal are still significant, but are smaller than those at the mouth of the Paraná river system, demonstrates that although the Golden mussel forms large colonies quickly, its success rate in colonization is not uniform.

Characteristics of L. fortunei responsible for its expansion, and factors that limit its growth

            The remarkable expansion of L. fortunei in South America and factors that have increased or inhibited its spread have been analyzed in careful studies. Several key elements have been found in the mussels’ successful colonization – (1) a lack of natural competitors for habitat, (2) an ability to colonize a variety of locations, (3) an amenability or adaptability to South American waters’ temperatures and composition, and (4) a short maturation and sexual reproduction cycle.

L. fortunei has little competition for its ecological niche. In the La Plata estuary, it is the only mussel species that attaches byssally to hard substrates, is epifaunal, and is well suited for freshwater regions (Darrigan, 2002). It has quickly become a major part of native fishes’ diets, and in general seems to have found an unfulfilled space in these aquatic ecosystems (Paolucci, Cataldo, Fuentes, & Boltovskoy, 2007). Although this lack of competition for habitat appears to have benefited the golden mussel, it is not necessarily vital for its development. This is illustrated by the fact that the Zebra mussel, which colonizes waterways in a similar manner to L. fortunei, has overtaken areas with and decimated pre-existing native mussel populations in North America (Karatayev, 2007).

The Golden Mussel is also successful because it can colonize a large variety of areas. L. fortunei produces free-swimming larva, which allows for a great amount of spreading nine months out of the year. After the initial, free-swimming stage, these larvae develop a “foot,” which can and will attach to any solid surface. This includes grains of clay or silt, the shells of other mussels, and industrial equipment such as pipes and condensers (Cataldo & Boltovsky, 2000).

The temperatures of most South American inland water bodies appear to be favorable for L. fortunei’s advance. This is important for the species’ success, as we can see from a 1995 study, which determined that the mussel’s growth reproductive cycle varies greatly according to temperature. Golden Mussels begin to reproduce in temperatures above 15-17°C (Cataldo & Boltovsky, 2000), and populations have been observed in water up to 32°C (Darrigan, 2002) A similar study in 2002 determined that L. fortunei’s filtering processes reach their peak between 20 and 25˚ C (Sylvester et al., 2005). Larvae are predicted to survive in temperatures from 16 to 28˚C, while adults can survive in water from 8 to 32˚C (U.S.A.C.E.). This suggests that the Golden mussel will be more abundant in the southern parts of North America, where the Zebra mussel, which has an ideal temperature of 12 to 24˚, is not as ecologically stable. Additionally, the golden mussel has been shown to be dependent on low levels of salinity, thus containing the species’ colonization to fresh or mostly freshwater areas. Specifically, L. fortunei is not likely to survive in water with a salinity of 2 ppt for greater than a year (Angonesi, da Rosa, & Bemvenuti, 2008). It should also be noted that L. fortunei’s umbonated larvae are extremely vulnerable to prolonged oxygenation or chlorination of their water. So far the mussel has not naturally encountered that obstacles in its colonization (Cataldo & Boltovsky, 2000).

L. fortunei typically mature sexually after one year (U.S.A.C.E.).  They are a typically dioecious species, and larvae are fertilized externally. As mentioned above, the larvae are free swimming, and attach to almost all available hard substrates. Evidence of L. fortunei’s fast reproductive rate was given in a 1998-1999 study in the La Plata estuary, where a pipe wiped clean of all specimens by high summer temperatures will be covered with a dense growth of L. fortunei within six to eight months (Cataldo & Boltovsky, 2000).

Other factors related to the success of an invasive species that are possessed by L. fortunei were listed in Morton’s 1996 study as “high fecundity…gregarious behavior; some form of association with human activities…suspension feeding… [and] the ability to repopulate previously colonized habitats” (ref. Darrigan, 2002). 

Impact in South America

The arrival of the Golden Mussel has had both positive and negative outcomes in the economies and environments of countries it has invaded. Argentina, Bolivia, Uruguay, Paraguay and Brazil have found a significant increase in the total annual freshwater fish harvest. Industries in these countries have also experienced difficulties and rising operational costs in using the affected waterways due to “macrofouling,” or the growth of life forms on non-living hard surfaces (Darrigan, 2002). Environmentally, the Golden mussel has increased benthic densities (Sylvester et al. 2007), become a major food source for at least one species of native fish (Paoulucci et al., 2007) and reduced populations of native invertebrates.

Limnoperna fortunei larvae were found to be the most important food source, in terms of biomass and nutrient content, for multiple taxa of larval fish in main channels of the Paraná river. L. fortunei was also found to be the second most important food source for a variety of larval fish in the marginal lagoons San Nícolas and El Saco, which are attached to the Paraná river system. The fish species that consumed the highest percentages of L. fortunei were also the most abundant local species (Paolucci et al., 2007). The vital role of the mussel in local fish’s diets is also visible in the Río de la Plata, where L. fortunei constitutes the main food source of the native “boga” fish (Penchaszadeh et al. 2000). Between 1992-93 and 2000-2001, the total amount of freshwater fish harvested multiplied 2.4-fold (Boltovskoy et al., 2006). Although this is not necessarily a direct result of l. fortunei’s introduction, the mussel’s integral role in native fish diets seems to indicate a correlation.

“Macrofouling” of indisustrial pipes and waterways in Argentina has caused problems for Hydroelectric power stations, nuclear plans, water treatment stations, distilleries and refineries (Boltovskoy et al. 2006). Macrofouling, or the deleterious growth of large organic material on a substrate, occurs in several parts of the Golden Mussels’ life cycle. First, when L. fortunei forms a colony on a hard surface such as pipes or filters, the water intake lowers and the water pressure may be reduced. The water in the pipes may become polluted, and the pipes themselves are often corroded. When the colonies die en masse due to temperature or water content, corrosion and pollution are compounded by large quantities of empty shells. These processes result in expenses to companies for cleaning, repairs, and lowered productivity (Boltovskoy et al. 2006, Darrigan 2002).

L. fortunei increases benthic densities through filtering of the surrounding water. After mussels filter nutrients from the water, they will precipitate organic material onto the surfaces they are attached to (or ‘substratum,’). This material settles in the benthic, or bottom, layer of the body of water, which increases the complexity of the substrata by providing new microhabitats on, under and in between shells. The presence of mussels has been found to increase numbers, biomass, and diversity of invertebrate species associated with the mussel bed. This growth may be related to increased sedimentation, but is almost certainly related to the new microhabitat (Sylvester et al., 2007.) However, in another study L. fortunei was found to displace native species of mollusks, and other potential displacements were suggested (Darrigan 2002).

Potential advance into North America

Although L. fortunei can be transported through natural spawning, attachment to recreational vessels and other various techniques, the most important mechanism of transport is commercial vessels. The likelihood of invasion in new areas is determined by the probability of introduction and environment suitability (Boltovskoy et al. 2006).  As the number of ports that have been invaded grows, so does the likelihood that the Golden mussel will be transported to North America through the ballast water of international trade ships.

In terms of ecological suitability, L. fortunei shares key habitation characteristics with the Zebra mussel (byssal attachment to hard substrata), which has successfully colonized much of North America. Significantly, L. fortunei not only tolerates warmer temperatures, lower levels of oxygen and calcium, and higher levels of pollution than the Zebra mussel, but also spawns for nine months out of the year, while the Zebra spawns for three (Boltovskoy et al. 2006). These factors indicate that the economic damage caused by the Zebra mussel could be less significant than the problems created by L. fortunei. It is important to note, however, that the environmental impact of the Golden mussel may or may not be similarly damaging – as mentioned, it has been found to assimilate much better than the Zebra mussel into the diet of native species (Paolucci et al. 2002), but it has also been found to displace native species (Darrigan 2002).

Conclusion 

Although the effects of Limnoperna fortunei on South American ecosystems and economies has been profitable in some areas, the remarkable ability of this species to spread out from original points of invasion and its unusual compatibility with American water systems makes the advance of this species undesirable. Techniques that would effectively prevent this advance include stringent examination of commercial ballast water and possibly private vessels as well as careful observance of waterways with international traffic. Temporarily oxygenating or otherwise disrupting the water supply in order to annihilate populations would most likely prove difficult, expensive and harmful to other species, removing individuals before they can get into the water supply or colonize substrata would appear to be the most effective strategy.

 

References

Angonesi, G. L., da Rosa, N.G., Bemvenuti, C.E. (2008). Tolerance to salinities shocks of the invasive mussel Limnoperna fortunei under experimental conditions. Iheringia. Série Zoologia, 98.

Bergonci, P.E.A., Mansur, M.C.D., Pereira, D., Pinheiro dos Santos, C. (2009). Population samplings of the golden mussel, Limnoperna fortunei, (Dunker, 1857), based on artificial ceramic substrate. Biotemas, 22, 85-94.

Boltovskoy, D., Correa, N., Cataldo, D., Sylvester, F. (2006). Dispersion and ecological impact of the invasive freshwater bivalve Limnoperna fortunei in the Río de la Plata watershed and beyond. Biological Invasions, 8, 947-963.

Cataldo, D.H., Boltovskoy, D. (2000). Yearly reproductive activity of Limnoperna fortunei (Bivalvia) as inferred from the occurrence of its larvae in the plankton of the lower Paraná River and the Río de la Plata estuary (Argentina).  Aquatic Ecology, 34, 307-317.

Darrigan, G. (2002). Potential impact of filter-feeding invaders on temperate inland freshwater environments. Biological Invasions, 4, 145-156.

Darrigan, G., Ezcurra de Drago I. (2000). Invasion of the exotic freshwater mussel Limnoperna fortunei in South America. The Nautilus, 114, 69-73.

Karatayev, Alexander Y., Boltovskoy, D., Padilla D.K., Burlakova L.E. (2007). The invasive bivalves Dreissena Polymorpha and Limnoperna fortunei: Parallels, contrasts, potential spread and invasion impacts. Journal of Shellfish Research, 26, 205-213.

Maroñas, M.E., Darrigan, G.A., Sendra, E.D., and Breckon, G. (2003). Shell growth of the golden mussel, Limnoperna fortunei (Dunker, 1857) (Mytilidae), in the Río de la Plata, Argentina. Hydrobiologia, 495, 41-45.

Paolucci, E.M., Cataldo, D.H., Fuentes, C.M., Boltovskoy, D. (2007). Larvae of the invasive species Limnoperna fortunei (Bivalvia) in the diet of fish larvae in the Paraná River, Argentina. Hydrobiologia, 589, 219-233.

Penchaszadeh, P.E., Darrigan, G., Angulo, C., Averbuj, A., Brögger, M., Dogliotti, A., Pírez, N. (2000). Predation of the invasive freshwater mussel Limnoperna fortunei (Dunker, 1857)(Mytilidae) by the fish Leporinus obtusidens Valenciennes, 1846 (Anostomidae) in the Rio de La Plata, Argentina.  Journal of Shellfish Research, 19, 229-231.

Sylvester F., Dorado J., Boltovskoy D., Juárez Á., Cataldo D. (2005). Filtraiton rates of the invasive pest bivalve Limnoperna fortunei as a function of size and temperature. Hydrobiologia, 534, 71-80.

Sylvester, F., Dorado, J., Boltovskoy, D., Juárez, Á., Cataldo, D. (2007). The invasive bivalve Limnoperna fortunei enhances benthic invertebrate densities in South American floodplain rivers. Hydrobiologia, 589, 15-27.

United States Army Corps of Engineers, Aquatic Nuisance Species Research Program. Golden Mussel – Limnoperna fortunei. Retrieved from http://el.erdc.usace.army.mil/ansrp/limnoperna_fortunei.pdf

 

National Invasive Species council website with definition of invasive species

 

 

 

 

 

 

 

honors 292r respsonse

So, I posted this on my other blog, too...but I wanted to put it on here. The end. ( : 

Jessie Riddle

Honors 292R

October 31, 2009

Dr. Kenneth R. Miller

            Dr. Miller’s lecture on evolution and the debate surrounding scientific education in the United States gave me a reason to think, and also reminded me that I greatly admire Charles Darwin and his philosophies.

            As a student at BYU in several biology courses, I have lots of questions on a daily basis about the process of speciation in the history of the world, and how that relates to what I believe. I see the ‘evolution’ of the landscape around me, the spiritual ‘evolution’ I experience as I process new information and feelings and grow in my personal development. I also read about the evolution of matter and our physical bodies – the materials that make up the world we know.

In the face of all this information, two things seem clear to me. First, we are built out of the generations of people that have preceded us. Second (to quote my father), we are more than the sum of our parts.

I enjoyed learning about the recent transitory fossil discoveries from Dr. Miller. I was also interested to learn about the court cases that have been causing such a separation of ideas in the neighborhoods of my country. I agreed with Dr. Miller in his final analysis – this does not have to be a divisive issue. Although I’m sure people will continue to argue about evolution and God, I thought the final quote form Darwin’s Origin of Species may have resonated more deeply with me than anything else in the lecture – “Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone circling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.”