BIOLOGY

Lection 6. Evolutionary biology

First systematics of animals

Aristotle

(384-322 BC)

Plato and Aristotle

Viviparous

(Vivipara)

Cetaceans

(Cetacea)

Birds (Aves)

Oviparous

(Ovipara)

Fishes (Pisces)

“Animals with

blood”

Soft-bodied

(Malacia)

Soft-shelled

(Malacostraca)

Insects

(Insecta)

Armoured

(Ostracoderma)

Zoophytes

(Zoophyta)

“Animals without

blood”

Plants

Minerals

Animals

(with and

without

blood)

Humans

Aristotle’s

«Ladder of life»

• Proposed the principle of

hierarchic classification of

plants and animals

• Made the first (artificial)

system of living organisms

(“Systema Naturae”)

• Gave a definition of the

species

• Introduced the binary

nomenclature to determine

the species

• Creationist. Considered

species unchangeableCarolus Linnaeus

(1707-1778)

Making of hierarchic classification

Kingdom

Subkingdom

Division

Phylum

Class

Order

Family

Genus

Species

Making of hierarchic classification

Offered by

Linnaeus

«System of Nature» (1735)

«System of Nature» of C. Linnaeus

Class Mammals

Class Amphibians (incl.

Reptiles)

Class Insects (incl.

Spiders and Myriapods)

Class Birds

Class Fishes

Class Worms (most

invertebrates)

Kingdom

Minerals

(Lapideum)

Kingdom

Plants

(Plantae)

Kingdom

Animals

(Animalia)

Jean-Baptiste

Lamarck (1744-1829)

First theory of evolution

• Proposed the term "biology" and

“invertebrate zoology"

• Created the first theory of

evolution. Its main statements:

• "The use of the organ leads to its

development, and the disuse – to

its disappearance"

• "Under the influence of exercise or

non-exercise the organs change

and resulting changes are

inherited"

• The reason for the evolution was thought to be "inner desire

for self-improvement of organisms"

“Gradations” of J.-B. Lamarck

(«Philosophy of Zoology», 1809)

14. Mammals

13. Birds

12. Reptiles

11. Fishes

8. Annelids

7. Crustaceans

6. Arachnids

5. Insects

4. Worms

3. Radiates

2. Polyps

1. Ciliates

10. Mollusks

9. Cirripedians

Inve

rteb

rate

s

Homological and analogical organs

Analogical organs – wings of insects and vertebrates

Structure of placoid scales of shark and human tooth

Dentine

Enamel

Dentine

Enamel

Pulp

Examples of homological organs

Middle ear bones and bones of lower jaw

Examples of homological organs

Eye of fish and cephalopod mollusk

Examples of analogical organs

Evolutionary theory of Charles Darwin

Charles Darwin

(1809-1882)

«The Origin of

Species…» (1859)

Travel of «Beagle» (1831-1836)

Types of variability after Darwin

Variability of the

beak shape in

Galapagos

finches

1. “Certain" (non-inherited, ~ modification)

2. “Uncertain" (inherited, ~ mutation)

3. Correlative (“White cats with blue eyes are deaf”)

Thomas-Robert

Malthus

(1766-1834)

Geometric progression of

reproduction

Main statements of Darwin’s theory

• Geometric progression of reproduction results in a

competition for resources

• Its consequence - the struggle for existence (the diverse

relations of species with each other and with environment)

• The uncertain variability leads to benefit of some individuals

over other ones

• A consequence of the struggle for existence - natural

selection (survival of the fittest), eliminating individuals with

harmful changes

• Evolution is an adaptive process

• Divergence of characters within the species leads to

speciation

Speciation according to Darwin (principle of divergence)

Rudimentary hind limbs of whale

Rudimentary hind limbs of boa Darwin’s tubercle

Proofs of evolution: rudiments

Hairy human Dolphin with 4 flippers

Human “tail”

Proofs of evolution: atavisms

Mammal-like reptile

Early amphibian First bird Archaeopteryx

Proofs of evolution: paleontology

Examples of sexual dimorphism in animals

Sexual selection

Idea of “evolutionary tree”

• The idea of "evolutionary tree"

• Biogenetic law ("ontogenesis is

the recapitulation of phylogeny")

• The method of "evolutionary

triad"

Ernst Haeckel

(1834-1919)

Embryonic development of vertebrates (after Haeckel)

Biogenetic law