Evolutionary biologists

Lazcano, an evolutionary biologist, and Miller, an experienced prebiotic chemist, believe that the most important bottlenecks in the biogenesis process leading from the primeval soup to the RNA world, and thence to cyanobacteria, are the following ... 

Although not fully understood, the methanogens place new challenges to the evolutionary biologists for further explanation in terms of the development of early life un earth and may be very valuable toward understanding life on extraterrestrial budicv as these may he explored over future years. 

Intriguing as this scenario may sound, though, critical details are overlooked. The question we must ask of this indirect scenario is one for which many evolutionary biologists have little patience but how exactly ... 

In a review of Darwin s Black Box for the MIT-published Boston Review, University of Rochester evolutionary biologist Allen Orr rejected out of hand the maybe-a-toothpick-turned-into-a-mousetrap reasoning of Kenneth Miller. 

The above comments reflect the trepidation that we feel as chemists, who do not profess to be either paleontologists or evolutionary biologists, in discussing this wide-ranging problem. It is evident in what has already been presented in this article that a-lactalbumin and lysozyme have important evolutionary relationships that involve divergence and/... 

Another hot topic among evolutionary biologists is the monophyletic versus polyphyletic status of archaebacteria. At the moment, there are no data in the... 

Although the establishment of the availability of the fundamental units of DNA, RNA and proteins was a critical component to the investigation of the origin of biological molecules and life on Earth, the simple presence of these molecules is a long step from functioning cells. Scientists and evolutionary biologists propose a number of methods by which these molecules could concentrate into a crude ceU surrounded by a primitive membrane. 

Houle As an evolutionary biologist, I think there is an explicit connection between variation and the state of a population. Variation is how you got where you are now. You can t think about evolution without thinking about variation. This is a separate issue from Geoffrey s point, which is saying that making inferences about variation is part of what mental architecture must be about. 

Faced with the formidable difficulties of estimating fitness, evolutionary biologists have turned to estimates of the life-history parameters that collectively determine fitness. Fortunately, these are easier to measure than fitness. For example, in the simple case of a stable population without parental care, fitness is the product of survival to age x (/x) times the rate of reproduction at age x (mx), integrated over the whole lifespan. A convenient approximation is the sum of survival and reproduction over a discrete series of ages. Then fitness of genotype i follows from the expected number of offspring, W, an individual has during its lifetime as ... 

Fisher s fundamental theorem (1958) states that selection removes additive genetic variance, and thus should diminish narrow sense heritability. Because of Fisher s argument (which is mathematically correct), scientists have argued until recently that additive heritability was prima facie evidence that the trait was evolutionarily neutral (e.g. Tooby Cosmides 1990). Flowever, the ubiquity of additive genetic variation, even for traits subject to strong selective forces, has forced evolutionary biologists to try to account for the routine violations of Fisher s fundamental theorem. 

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