Maldaptation, Extinction and Natural selection
Hi all, I am having an interesing discussion at the moment about Natural selection. The context is a single population of individuals that, due to changes in the environment, are now maladapted and the population is reducing in size. Based on the often used definition of differential reproduction, when there is not much to differentiate with, there is no longer differential selection, and as such, no natural selection. However, they are maladapted, so unfit to survive. Any opinions about this nice contradiction? Cheers, Kim -- http://www.kimvdlinde.com
Re: Tick talk
I trust it is the writer of the news article, and not the expert Thomas Mather, who thinks that ticks are insects... 1880's: There's lots of good fish in the sea W.S. Gilbert 1990's: Many fish stocks depleted due to overfishing, habitat loss, and pollution. 2000's: Marine reserves, ecosystem restoration, and pollution reduction MAY help restore populations. \ \ \ \ \ - - _ - \ \ \ \ \ - _ -\ - -( O \ _ - -_ __ / - -/ -/// _ __ ___/ /// / Judith S. Weis, Professor Department of Biological Sciences Rutgers University, Newark NJ 07102 [EMAIL PROTECTED] Phone: 973 353-5387 FAX 973 353-5518 http://newarkbiosci.rutgers.edu/faculty/weis.html
safety of research in Chad?
Dear Eco-loggers, I'm would like to collect some data near lake Chad in the country of Chad. There are currently travel advisories for the country but such advisories are often over-stated. I was wondering if anyone could please give me a proper assessment of the safety of the working conditions in the country or could recommend where I could contact scientists currently working in the country for an true assessment of the situation. Sincerely, Renee Renee A. Richer, PhD Assistant Professor Director, Environmental Conservation and Research Center American University of Armenia 40 Baghramian Avenue #136 Yerevan, Armenia 375019 [EMAIL PROTECTED] (374-10)51-26-90
Job: field technician, bird and bat movement patterns, Appalachians
FIELD TECHNICIAN (1) needed from approximately 15 Aug to 30 October for research project on bird and bat movement patterns through the Appalachian Mountains of Virginia, West Virginia and Maryland. The project employs marine radar technology to monitor spatial and temporal patterns of nocturnal bird/bat movements during southward migration. Duties include setting up, monitoring and maintaining radar and computer equipment and archiving data for analysis. Experience using basic computer programs like Windows XP, MS Excel and data compression software required. Must be willing to work unusual hours (early morning or night), be able to lift heavy objects (75-100 pounds) and have a valid drivers license. Must be able to work independently or part of a team. Background in bird/bat migration useful but not required. Salary $1500-1800/month DOE. Lodging and meals provided. Send cover letter of interest, resume, and three references by 1 August to David Mizrahi, PhD, Cape May Bird Observatory, 600 Route 47 North, Cape May Court House, NJ 08210, mailto:[EMAIL PROTECTED][EMAIL PROTECTED] -- David S. Mizrahi, Ph.D. Vice-president for Research New Jersey Audubon Society 600 Route 47 North Cape May Court House, NJ 08210 Ph: 609.861.0700 fax: 609.861.1651
Re: Maldaptation, Extinction and Natural selection
Actually, in the below senario there is Natural Selection and it is = working. Since those organisms are now maladapted, and declining to = extinction Natural Selection is selecting them for extinction. =20 Natural Selection selects against unfit organisms, not for fit ones. = This is much different from selecting for the most fit organisms. This = is particularly important because it is this selection against = maladapted individuals that maintains diversity within a population. If = Natural selection selected for a particular genome, the entire = population would rapidly become homogeneous. The heterogeneity dictates = that the population has many different characteristics, some of which = are ideally adapted to the current climatic/habitat conditions, others = are only marginally adapted to this optima. As the climates change or = habitats success, dominance of different traits shifts do to = differential selection pressure across a continuum of from least to most = adapted. The least adapted will decline, possibly becoming extirpated. = The most adapted will proliferate and dominate. Another shift in optima = occurs and the population traits shift in response. =20 =20 This is not unlike a place of employment. People who can't do the job = are fired. But there is wide variation in the ability of employees to = do the same job. Some of these receive raises and promotions due to = their ability to excel while others are demoted or do not receive = raises. This array of employees remains employed and functioning in the = workplace, they all reproduce! =20 =20 To learn more about this interesting relationship it would be good to = get yourself a copy of Dawkin's The Selfish Gene. In my opinion, it = is the best evolution book out there (still) because anyone can grasp = what is written. My genetics class is required to read this! =20 =20 I hope that answers your question and if you need clarification, feel = free to send an email!=20 =20 VISIT HERPETOLOGICAL CONSERVATION AND BIOLOGY www.herpconbio.org = http://www.herpconbio.org=20 A New Journal Published in Partnership with Partners in Amphibian and = Reptile Conservation and the World Congress of Herpetology. =20 Malcolm L. McCallum Assistant Professor Department of Biological Sciences Texas AM University Texarkana 2600 Robison Rd. Texarkana, TX 75501 O: 1-903-223-3134 H: 1-903-791-3843 Homepage: https://www.eagle.tamut.edu/faculty/mmccallum/index.html =20 From: Ecological Society of America: grants, jobs, news on behalf of Kim = van der Linde Sent: Sat 7/8/2006 11:36 PM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Maldaptation, Extinction and Natural selection Hi all, I am having an interesing discussion at the moment about Natural selection. The context is a single population of individuals that, due to changes in the environment, are now maladapted and the population is reducing in size. Based on the often used definition of differential reproduction, when there is not much to differentiate with, there is no longer differential selection, and as such, no natural selection. However, they are maladapted, so unfit to survive. Any opinions about this nice contradiction? Cheers, Kim -- http://www.kimvdlinde.com
Ancient description of ecosystem dynamics?
I just ran across this bit of writing from almost 2,000 years ago: All that is born, all that is created, all the elements of nature are interwoven and united with each other. All that is composed shall be decomposed: everything returns to its roots: matter returns to the origins of matter. This is part of the fragmentary Gospel of Mary found in Cairo in 1896 but only recently studied and translated (this translation of the Coptic is by Jean-Yves Leloup). Authorities say it was probably written during the second century C.E. I was amazed that someone thought and wrote along these lines so long ago. It succinctly describes what an ecosystem is, using terms suggestive of more modern concepts such as biolgical communities, species interactions, mutualism, biogeochemical cycling, and decomposition regimes. Does anyone know of other ancient writings that come this close to today's concepts of how an ecosystem operates? Or is this unique? We tend to think that much of this understanding arose only within the last 100 years. Warren W. Aney Senior Wildlife Ecologist 9403 SW 74th Ave Tigard, OR 97223 (503)246-8613 (voice) (503)246-2605 (fax) [EMAIL PROTECTED] (email)
