Bio 201 F09 True lect 5 (L5)v4r

Bio 201 F09 True lect 5 (L5)v4r - Todays factoid Male...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Today’s factoid ‘Male Biological Clock’ story posted on ‘Biology in the News’ folder on BB intelligence tests given to young children show significantly lower scores for children with 50 yr old fathers versus children of 20 yr old fathers – although socioeconomic effect was larger http://images.inmagine.com/168nwm/valuestock/unz215/ u17351127.jpg
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
small population non-random mating recurrent mutation migration selection Causes for Evolution
Background image of page 2
Adaptation • A heritable trait that increases the fitness of the individual with the trait relative to others that lack the trait. – Improves “performance” in that environment • Usually thought of as response to environmental conditions – Although sexually selected traits are also adaptations - to sexual selection
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sexual Selection • Originally proposed by Darwin • Selection favoring mating success of an individual/genotype relative to other individual/genotypes in that population • Can oppose natural selection How?? (keep this question in mind during next slide)
Background image of page 4
http://www.hlasek.com/ foto/ euplectes_progne_ad6 372.jpg Classic experiment by Malte Andersson on long-tailed widowbirds ( Euplectes progne ) in Africa What about natural selection on this trait?
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Selection can also maintain genetic variation • One mechanism:Any kind of selection that favors heterozygotes over homozygotes will help to maintain polymorphism – “heterozygote advantage” or “heterosis”
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/22/2009 for the course BIO 201 taught by Professor True during the Fall '08 term at SUNY Stony Brook.

Page1 / 27

Bio 201 F09 True lect 5 (L5)v4r - Todays factoid Male...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online