Download Processes of Evolution Chapter 8 part 2

Processes of Evolution
Chapter 8 part 2
Fig. 18-5a, p. 282
Fig. 18-5b, p. 282
Fig. 18-5c, p. 282
Predation and Peppered Moths
Predation and Rock-Pocket Mice
 In rock-pocket mice, two
alleles of a single gene
control coat color
 Night-flying owls are the
selective pressure that
directionally shifts the allele
frequency
Time 1
Number of individuals
in population
Stabilizing Selection
Range of values for the trait
Time 2
Time 3
Stepped Art
Fig. 18-8, p. 284
Fig. 18-10a, p. 285
Fig. 18-10b, p. 285
Fig. 18-10c, p. 285
Evidence of Evolution
 Biogeography
 Fossils/geology
 Anatomy
•
•
•
•
Homologous structures
Analogous structures
embryos
Vestigial structures
 Molecular biology
 Field and lab studies
Patterns in Biogeography
Biogeography
Marsupials
evolution.berkeley.edu/evosite/lines/IVCexperiments.shtml
en.wikipedia.org/wiki/Image:Kangaroo_and_joey03.jpg
A 420 mya
B 237 mya
C 152 mya
D 65.5 mya
E 14 mya
Fig. 17-17, p. 273
About Fossils
 Fossils are remnants or traces of organisms
that lived in the past
 give us clues about evolutionary relationships
 The fossil record will always be incomplete
Fossils
 Fossils
• Remains of bones,
teeth, shells,
seeds, spores, or
other body parts
 Trace fossils
• Evidence of an
organism’s
activities (nests,
trails, footprints,
burrows, bore
holes, eggshells,
feces)
Fossils
Transitional fossils
• Many fossils show a clear
transition from one species,
or group, to another.
Archaeopteryx
http://chem.tufts.edu/science/evolution/horseevolution.htm
http://www.talkorigins.org/faqs/faq-transitional/part2a.html
http://evolution.berkeley.edu/evolibrary/article/lines_03
http://evolution.berkeley.edu/evolibrary/home.php
A Whale of a Story
New Links in the
Ancient Lineage of Whales
New Links in the
Ancient Lineage of Whales
Dating Pieces of the
Puzzle
 Radiometric dating
• Ex: uranium 238 →
lead 206
 Half-life
• time it takes for half of
a radioisotope’s atoms
to decay into a
daughter element
Fig. 17-14a, p. 270
Fig. 17-14b, p. 271
Anatomy- comparative morphology
 Homologous structures
• Similar body parts that
reflect shared ancestry
• The same genes direct
their development
 Analogous structures
• Body parts that evolved independently in
separate lineages in response to the same
environmental pressure
Vestigial
Structures
 As evolution progresses,
some structures get sidelined as they are not
longer of use.
coccyx
limb
bud
Fig. 17-3, p. 261
Anatomy-embryos
 Embryos of many vertebrate species develop in
similar ways
Molecular Evidence
Comparing Cytochrome b Sequences
Similar Genes
HUMAN
CHIMPANZEE
GORILLA
CCAAGGTCACGACTACTCCAATTGTCACAACTGTTCCAACCGTCACGACTGTTGAACGA
CCAAGGTCACGACTACTCCAATTGTCACAACTGTTCCAACCGTCATGACTGTTGAACGA
CCAAGGTCACAACTACTCCAATTGTCACAACTGTTCCAACCGTCACGACTGTTGAACGA
Genetic code of chimps and gorillas is almost identical to humans
Field/Lab Evidence-Antibiotic resistance
Reproductive Isolation
 Speciation
• Evolutionary process by which new species form
 Biological species concept- species are
populations of organisms that interbreed under
natural conditions
Allopatric Speciation
The Inviting Archipelagos
A A few individuals of a
mainland species reach
isolated island 1. In the new
habitat, populations of their
descendants diverge, and
speciation occurs.
B Later, a few
individuals of a new
species colonize
nearby island 2.
Speciation follows
genetic divergence
in the new habitat.
C Genetically different
descendants of the
ancestral species may
colonize islands 3 and 4
or even invade island 1.
Genetic divergence and
speciation may follow.
Fig. 18-21a, p. 293
Akepa
Akekee (L.
Nihoa finch Palila(Loxioides
(Loxops
caeruleirostris)
(Telespiza
bailleui)
Mamane
coccineus)
Insects,
ultima)
Insects, spiders spiders, some Insects, buds,
seeds ripped
from buds
nectar; high
seeds, flowers, from pods;
twisted apart
buds,
mountain rain seabird eggs;
by bill, some
flowers,
forest
rocky or
nectar; high
shrubby slopes some berries,
mountain rain
insects; high
forest
mountain dry
forests
Maui parrotbill
(Pseudonestor
xanthophrys)
Rips dry branches
for insect larvae,
pupae, caterpillars;
mountain forest
with open canopy,
dense underbrush
Apapane
(Himatione
sanguinea)
Nectar, especially
of ohialehua flowers;
caterpillars and other
insects; spiders;
high mountain
forests
Fig. 18-21b, p. 293
Poouli
Maui Alauahio Kauai Amakihi
Akiapolaau
(Melamprosops (Paroreomyza (Hemignathus (Hemignathus
phaeosoma)
montana)
kauaiensis)
munroi)
Probes, digs
Bark-picker;
Tree snails,
Bark or leaf
insects in
insects, some insects, spiders, insects from
big trees; high
nectar; high
understory;
nectar; high
mountain rain
last known
mountain rain mountain rain
forest
forest
male died in
forest
2004
Akohekohe
(Palmeria
dolei)
Mostly nectar
from flowering
trees, some
insects, pollen;
high mountain
rain forest
Iiwi (Vestiaria
coccinea)
Mostly nectar
(ohia flowers,
lobelias, mints),
some insects;
high mountain
rain forest
Fig. 18-21c, p. 293
Extinction
• The irrevocable loss of a species from Earth
 Background extinctions- extinctions that occur
at lower rates during periods periods other than
mass extinctions
 Mass extinctions
• Extinctions of many lineages, followed by adaptive
radiations
• Five catastrophic events in which the majority of
species on Earth disappeared