Evolution – evidence and types of data

Natural Selection

Industrial melanism

The Fossil Record

Geologic strata in the Grand Canyon, Arizona

Green River Formation, WY and UT.

Eocene in age

The Fossil Record

The Fossil RecordTimelines

Fossils: Links between groups

Major Transitions: from Fish to Amphibian

Lobefin fish

Early amphibian

Eustenopteron

Ichthyostega

Fossil Record

Major Transitions: from Fish to Amphibian

Acanthostega

Amphibian-like fish

The Link

Fish

Amphibian

Ichthyostega

Acanthostega Eustenopteron

The FossilsAll represented in the fossil record

Comparative Anatomy

Homologous structures

Comparative Anatomy

Analogous structures

Vestigial structure

Comparative Anatomy

Human appendix

Vestigial structure

Comparative Anatomy

Comparative Embryology

Molecular model of hemoglobin

Molecular Record

Molecular Record

A phylogeny or cladogram

The mechanics of change - Origin of Species and Speciation

What is a species?

Biological Species Concept (BSC)

BSC is about genetic Isolation

Genome = Individual

Gene pool = Population

Haemulon flavolineatum

(Canis latrans x Canis familiaris)

CoydogCoyote x domestic dog

Isolating Mechanisms

Premating Isolating mechanisms

Isolating Mechanisms

Premating Isolating mechanisms

Postmating Isolating mechanisms

Premating Isolating mechanism

Habitat Isolation

Canis rufus

(red wolf)

Canis latrans

(coyote)

Habitat Isolation

Premating Isolating mechanism

Behavioral Isolation

Premating Isolating mechanism

Courtship coloration or displays in many animals

Behavioral Isolation

Colisa lalia (male)

(from India)

Premating Isolating mechanism

Behavioral Isolation

Premating Isolating mechanism

Temporal Isolation

Premating Isolating mechanism

Spawning marine sponge --

may involve temporal isolation

Premating Isolating mechanism

Mechanical Isolation

Premating Isolating mechanism

Gametic Isolation

Genetic isolation occurs in closely related species of sea urchins

Strongylocentrotus franciscanus

Strongylocentrotus purpuratus

Postmating Isolating

mechanisms

Postmating Isolating mechanism

Reduced hybrid viability

Postmating Isolating mechanismReduced hybrid fertility

Donkey (male)

Horse (female)

The hybrid: mule

This animal has no fitness.

“That’s about as useful as a pair of breedin’ mules”

Speciation

Speciation

Isolation

then

Divergence

Two Speciation Models

Allopatric speciation

Two Speciation Models

Sympatric speciation

Allopatric speciationA physical barrier creates isolation

Sciurus aberti kaibabensis

(North Rim, Grand Canyon)

Sciurus aberti aberti

(South Rim, Grand Canyon)

Allopatric Speciation: Islands

Darwin’s Finches

Galapagos Islands

Sympatric Speciation

Requires reproductive isolation WITHOUT

physical barrier

Is this possible?

Sympatric Speciation

Lake Mbo, Cameroun, Central Africa

Lake Mbo endemic cichlid fishes – 15 species

How did isolation occur?

Sympatric Speciation

Ophrys lutea Ophrys sicula

Two sympatric European orchids with two different and highly specialized pollinators.

Sympatric Speciation?

Lake Victoria, East Africa

Sympatric Speciation?Lake Victoria, East Africa

Very large radiation of endemic cichlid fishes

Adaptive Radiation

Hawaiian honeycreepers

Adaptive Radiation

Cichlid fishes in Great Lakes East Africa

Adaptive Radiation

Adaptive Radiation

Cichlid fishes in Great Lakes East Africa

Tertiary Period – 65 million years ago (mya)

Adaptive Radiation

Mammal Radiation

Adaptive Radiation

Biodiversity

Biodiversity

Extinction

Small population size

Devil’s Hole Pupfish

Cyprinodon diabolis

Extreme specialization

Koala bear

California condor

an orchid

Continental Drift and extinctions

Humans and Extinction

Steller' Sea Cow (Hydrodamalis gigas)

Pleistocene megafauna

Climate Change

Lake Victoria, East Africa

Humans and extinction

Lake Victoria cichlids – 100s of species

Add an introduced top carnivore …..

Nile perch

(Lates niloticus)

the result …….

………extinction.

Only habitat for most surviving Lake Victoria cichlids

Lake Victoria

Lake Tanganyika

Lake Malawi

Ivory-billed woodpecker (Campephilus principalis)

Extinction?

Classification and how we name things

Carl Linnaeus (1707-1778)

Father of modern classification

Carl Linnaeus1758

Foundations of Modern Classification

1738

Foundations of Modern Classification

18th Century

Percina pantherina

Binomial names

Carnegiea gigantea

Megaptera novaeangliae

Cyprinella lutrensis

Homo sapiens L.

Binomial names

Taxonomy and

Systematics

are the sciences of

Classification

…books everybody should have in their library

Common names are rarely standard and not international

“Corn”

“Bears”

Sciurus carolinensis

Domain Eukarya

Kingdom Animalia

Phylum Chordata

Class Osteichthyes

Family Salmonidae

Order Salmoniformes

Genus & species

Oncorhynchus mykiss

Classification – taxonomic characters

Classification – taxonomic characters

Phylogenetics

Haeckel (1879)

Family Anabantidae

African climbing perches

Phylogeny for the Anabantidae

Skeletal features

Anabantidae

Anabantid Jaw Structure

Hypothesis of evolutionary relationships

Classification and Phylogeny

A dinosaur phylogeny….

Classification on a very large scale

Relationships among the three domains

Relationships among the three domains

Domain Archaea

Domain Bacteria

Domain Eukarya

Biodiversity and Classification

Family Malapteruridae

African electric catfishes

“unsightly” --- G. Bell-Cross

“unpleasant” --- P.H. Greenwood

“repellent” and “bloated” --- P.B.N. Jackson

“…repulsive….barely needs description” --- R. A. Jubb

“filthy, flabby, nasty” and “…like a big fat slug” --- H. Copley

“…in every respect a revolting fish” --- H. Copley

Fifth Dynasty tomb relief at Ti, Egypt

Electric CatfishesServing medicine ….

Cavendish

Electric Catfishes

Serving science

Galvani Volta

Serving medicine ….

Family Malapteruridae

1990s –

Three species recognized

M. minjiriya

M. microstoma

Genus Malapterurus

M. electricus

M. minjiriya

M. microstoma

Genus Malapterurus

1969

1976

1789

M. electricus

Two distributions ill-defined …..

…with an impossibly vast distribution for M. electricus

Distributions of organisms follow patterns

Systematic Ichthyology --- how is it done?

Royal Museum of Central Africa

Tervuren, Belgium

Laboratory of Systematic Ichthyology

Characters

DATA

Standard len gth (mm)

-20

20

60

100

140

180

220

260

300

0 50 100 150 200 250 300 350 400

PC 1

-2.5

-1.5

-0.5

0.5

1.5

2.5

-2.5 -1.5 -0.5 0.5 1.5 2.5 3.5

1.8

93.7

Stan dard leng th (mm)

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

35 - 40 40 - 45 45 - 50 50 - 55 55 - 60 60 - 65 65 - 70 70 - 75 75

Data explored, patterns identified…..

Hypotheses formulated

Flanders

Flanders

Paris

The Result ---

Not three species …

19 species

Not three species……

but 19 species

Nilo-Sudanic Region

M. electricus

West African Rain Forests

M. teugelsi M. stiassnyae

M. barbatus

M. punctatusM. thysi

West African Rain Forests

Central African Rain Forests

M. gossei

M. melanochir

M. microstoma

M. polli

Genus Malapterurus

P. caudivittatus

P. parvus

P. cryptus

Genus Paradoxoglanis

P. caudivittatus

P. parvus

P. cryptus

(Genus Paradoxoglanis)

Mini-Electric Catfishes

Not three species

19 species

19 species …

…in 2 genera

Published Research