Download presentation
Presentation is loading. Please wait.
Published byDeirdre Glenn Modified over 8 years ago
1
Take Out The Following Labs SPECIATION MICROEVOLUTION & ALLELE FREQUENCY
2
“When The Student Is Ready, The Master Appears”- Buddhist Proverb
3
Cladistics Has Shown That Insects Have Evolved Through CONVERGENT evolution SIX DIFFERENT TIMES!
4
Evolution of Insects 75% of all animals on earth are insects Insects were NOT the first animals Evolved during the Devonian (~400 mya) The path of insect evolution is very different from all other animals
5
Different Models For Rate of Evolutionary Change Gradualism Slow, incremental changes in allele frequency and phenotype over time Punctuated Equilibrium Long periods of no change in allele frequency and/or phenotype interrupted by rapid “bursts” of drastic change
6
Divergent v. Convergent Evolution Divergent Adaptive Radiation Due to selective pressures, variations are favored and ancestral species become physically and reproductively isolated Convergent Organisms of different ancestry are acted upon by selective pressures that favor similar variations
7
How are these concepts addressed in the evolution of Geospiza?
8
Mainland
9
Windsor
10
Norcross
11
Warwick
12
Which factors were most influential in the evolution of Birgus latro?
13
Microevolution Lab Results Which atoll had highest frequency of black carapaces? Wotho Why? Founder’s Effect, Outbreeding or Selective Pressures? Founder’s effect. No outbreeding or selective pressures What about frequency of four legs? Same
14
Microevolution Lab Results How do frequencies of carapace color correlate with phenotypic frequencies? Direct relationship. Highest frequency of black correlates with highest frequency of recessive allele How do frequencies of appendages correlate with allele frequencies? More direct due to incomplete dominance
15
Microevolution Results Similarities with pollenpeeper analysis? Reproductive isolation amplifies single phenotypes Is artificial selection influencing any of the atolls? Lae, human selection against red Which atoll was most likely to exhibit Hardy-Weinberg equilibrium? Wotho, due to no selective pressures or outbreeding
16
What about convergent evolution?
18
Convergent Evolution & The Eye
19
The Kung & Steatopygia
20
Convergent Evolution
21
How do scientists evaluate the direction and pattern of evolutionary change?
22
Cladistics Clade: from Greek word klados (branch) Group of closely related organisms with shared derived properties
24
Cladogram Diagram showing time and direction of divergence (or, occasionally, convergence)
25
Defining Cladistics By Phenotypic Traits Plesiomorphy = Ancestral trait shared by members of a clade Apomorphy = a newly evolved trait that separates taxa from their clade
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.