{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ANT1Lecture18 - Anthropology 1 Winter 2008 Human...

Info icon This preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
Anthropology 1 – Winter 2008 Human Evolutionary Biology
Image of page 1

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

View Full Document Right Arrow Icon
A. africanus Sahelanthropus Orrorin Ardipithecus 1 2 3 4 5 6 A. afarensis P. boisei P. robustus A. anamensis A. garhi P. aethiopicus M Y A H. habilis H. ergaster Hominin phylogeny
Image of page 2
Which fossil species are more closely related to each other? First approximation: Assume species with similar phenotypes (skeletons) are closely related to each other Use degree of similarity to reconstruct evolutionary relationships (phylogeny) Phylogeny reconstruction
Image of page 3

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

View Full Document Right Arrow Icon
Time since divergence Phenotypic Distance First approximation works for neutral phenotypic features
Image of page 4
Problem with first approximation – Natural selection Natural can slow down or speed up divergence rates, invalidating first approximation Natural selection can confound phylogeny reconstruction in 2 ways Similar directional selection pressures Different amounts of stabilizing selection
Image of page 5

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

View Full Document Right Arrow Icon
Directional selection can cause problems because . . . Different types of similarities Analogy (homoplasy) Similarity that results when similar directional selection pressures produce similar adaptations Homology Similarity that results from closely shared ancestry (evolutionary history)
Image of page 6
Analogies can cause problems
Image of page 7

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

View Full Document Right Arrow Icon
Analogies can cause problems
Image of page 8
Consider 3 species Human Chicken Platypus Analogies can cause Problems
Image of page 9

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

View Full Document Right Arrow Icon
Consider 3 species Human Chicken Platypus Lactates Bipedal Human Yes Yes Chicken Yes Platypus Yes Analogies can cause Problems
Image of page 10
Consider 3 species Human Chicken Platypus Lactates Bipedal Human Yes Yes Chicken Yes Platypus Yes Analogies can cause Problems
Image of page 11

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

View Full Document Right Arrow Icon
Consider 3 species Human Chicken Platypus Lactates Bipedal Human Yes Yes Chicken Yes Platypus Yes Analogies can cause Problems
Image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern