Lecture 20&21

Lecture 20&21 - Australipithecus ("southern...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
BIOLOGY 1001: LECTURE 20 MORPHOLOGICAL INNOVATION AND THE HUMAN LINEAGE Time line in human evolution: Bony fishes: 450 million years Amphibia: 350 million Reptiles: 300 million Mammals: 190 million Placental mammals: 90 million Primates: 65 million Apes: 35 million Hominid: 6 million Major innovations from the fishes to the primates: 1.Lungs in Fishes 2.Paired walking appendages in Amphibia 3.More efficient lungs and waterproof skin in Reptiles 4.Extensive maternal care, endothermy, and large brains in Mammals 5.Larger brains in Primates ENDOTHERMY - utilization of metabolic energy to maintain constant body temperature ECTOTHERMY - utilization of external energy (e.g. sunlight) to maintain temperature HOMINID - all members of the human lineage since divergence from the apes, including the genus
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Australipithecus ("southern ape") and the genus Homo Factors associated with larger relative brain size in contemporary species: 1.Complex environment a.Distribution of food:fruit eaters > leaf eaters carnivores > herbivores b.Type of habitat: above-ground > burrowing animals 2.Reliance on memory: food-storing species > non-food-storing Fossil evidence shows that the genus Homo originated in Africa Genetic data also suggests African origins; mitochondria DNA variation suggests common female ancestor 0.2-1.0 million years ago Human genetics reveals patterns of diversification due to the micro-evolutionary principles of gene flow, drift, and selection....
View Full Document

This note was uploaded on 01/20/2010 for the course BIOL 1001 taught by Professor Fall during the Fall '08 term at Minnesota.

Ask a homework question - tutors are online