The idea of eugenics is still not comprehendible. The research journal Molecular Human Reproduction states questions that many people still ask like, why are two genders needed for reproduction? How come millions of sperm are produced by the males daily? Steve Ramm, a famous evolutionary biologist from Bielefeld University answers these questions and many more in his publication on sperm wars. He states that in the process of reproduction, a female will mate with different males at several times. But only the premier sperm will fertilize the egg, and this depends on the speed and amount of sperm transferred and the thickness of the semen.The best sperm fertilizes the egg. It may involve speed and amount of sperm transferred, and it may be useful for the seminal fluid to be viscous making it stick inside female reproductive tract to keep other sperm at bay.
Since sperms of one male compete with those of another, they need to adapt well. ‘Production of the optimal sperm takes place in the testis, during spermatogenesis,’ explains Ramm. Sperm is believed to be the most diverse kind of cell in the whole animal kingdom. Ramm’s article elaborate formation of different sperm cells. It states that is not only the amount and shape of sperm are important. The size of individual sperm cell may give a competitive advantage. Human sperms are small and swim with their tails, but there are spherical and crawling sperms or even giant sperm, bigger than the male that produces them.
Evolutionary biologists analyze how living organisms have developed over millions of years. According to Ramm, the primary concern is to understand why reproduction in animals happens in the way that it does. In the long-term, this knowledge helps reproductive biologists to alter sperm to increase the chance of fertilization genetically and help conserve endangered species.
Dr. Steven Ramm has been conducting research and one of his research topics was to identify characteristics of male animals enable them to reproduce successfully. In 2006, Ramm graduated with his doctorate from University of Liverpool (England) and later did research at University of Innsbruck (Austria) and University of Basel (Switzerland). He is heading the project ‘Functional and evolutionary genetics of seminal fluid.’ He is responsible for EU research project ‘Sperm Evolution.’
Article 2: Diet affects the evolution of birds
How diet has affected the evolution of the 10,000 bird species in the world is still a mystery to evolutionary biology. A study by Daniel Kissling of the Institute for Biodiversity and Ecosystem Dynamics (UvA) and colleagues from the University of São Paulo and the University of Utah shows how diet preferences have influenced bird diversification over millions of years. The findings were published in Nature Communications.
After seminal work by Charles Darwin, it’s known that dietary habits of birds can influence their development of like beak of Galapagos finches. Nevertheless, birds show an incredible diversity and dietary adaptations. How such various dietary preferences finally lead to variations in the diversification of birds has not been studied.
Researchers composed a diet dataset of nearly all bird species in the world together with a large phylogenetic tree that symbolizes relation of all bird species. They demonstrated that omnivorous bird descents have lower rates of speciation and higher rates of extinction than species that like specific food items like fruits. They also found that over evolutionary time, birds specialized on a particular food item frequently add other foods to their diets, resulting in evolving transitions into omnivory.
It is amazing to find that omnivores preferentially arise through changes, and not speciation,’ says lead author. Together with the low speciation rates and high extinction rates, these high transition rates show that omnivores come from more specialized birds that expand their diets, and not directly via speciation of omnivorous bird clades. According to Burin, this is brought by resource competition, climate instability, and deep-time availability of food resources.’ High transition rates to omnivory might come up in times when food is difficult to find or temporally unavailable.
Expanding these findings to the current human-driven changes on our planet competitive dynamics shifts are expected between generalists and specialists. It means that specialists are currently at higher risk of extinction than generalists. ‘This will change the ecology and evolution of life on Earth since generalists are favoured at the expense of specialists’, explains Kissling. Ultimately, this will affect the functioning of ecosystems and the services that nature provides to humanity.
Article 3: Evolutionary biology: New approach to tackle global challenges in food security, emerging diseases and biodiversity loss
Solving global challenges in food security, emerging diseases and biodiversity loss requires evolutionary thinking, argues a new study published online in Science Express that was co-authored by Bruce Tabashnik of the University of Arizona College of Agriculture and Life Sciences.
A team of nine scientists has reviewed progress in addressing a broad set of challenges in agriculture, medicine and environmental management using approaches that consider evolutionary histories and likelihood of rapid adaptation to human activities. The study sees an urgent demand for better implementation of evolutionary. Current efforts are deficient in reducing the accumulating costs from chronic disease and biodiversity loss
An evolutionary perspective give useful new ways to handle problems from agricultural pests, pathogens. Tabashnik and his colleagues at UA have been leading research to provide farmers with sustainable control of crop pests. A significant advance is genetic engineering of cotton and corn to produce proteins derived from the widespread soil bacterium. Integrating Bt cotton plants with other tactics has revived Arizona’s cotton industry.
Refuges plants lack Bt toxin gene and allow survival of insects susceptible to the toxin. Farmers plant refuges to make it unlikely for resistant insects to mate and produce resistant offspring. According to Tabashnik, the refuge strategy worked in Arizona while in India, farmers did not plant refuges and therefore pink bollworm rapidly evolved resistance to Bt cotton.
The refuge strategy can yield more efficient cancer treatments. Portions of tumors with little vascularization and small delivery of chemotherapeutic drugs may act as refuges holding tumor cell lines that are yet to be resistant to chemotherapy. According to the authors, compared to typical failures when oncologists try to eliminate a patient’s cancer with high drug doses, lower doses could be more successful.
The research of Michael Worobey, a professor in the UA has produced breakthroughs in understanding AIDS, flu epidemics and obesity while researchers with UA’s Arizona Genomics Institute and the iPlant Cooperative have traced the genetic codes of crop plants. Evolutionary biology has a lot potential and disregarding them may result in undesired outcomes.