Biodiversity & Evolution

manic lesson

Biodiversity

• also called biological diversity
• the term used to describe the variety of life on Earth and all of the natural processes

Bio

life

Diversity

variety

Evolution

is a change in the genetic make-up of an organism or specie over time

• Fossil evidences
• Anatomical evidences
• Molecular evidences
• Embryological evidences

Evidences of Evolution (F.A.M.E)

Fossil evidences

• this refers to the remnants of ancient organisms
• Paleontologists make initial estimates of the age through the position in the sedimentary rocks layer or strata

• Divergent Evolution
• Convergent Evolution

Kinds of Anatomical Evidences

Divergent Evolution

is the process by which particular specie evolves into two or more descendants or different forms in order to adjust to various environmental conditions

Homologous Structures

are those that are fundamentally similar but may not necessarily perform the same function which suggests common origin

Convergent Evolution

is the process by which unrelated or distantly related organisms evolve similar body forms, coloration, organs, and adaptations

Analogous Structures

pertain to the various structures in different species having the same appearance, structure or function but have evolved separately, thus, do not share common ancestor

Molecular Evidences

• the greater the similarity in amino acid sequence, the closer the relationship of the organisms
• the organisms which are similar in structure
• also possess similarity at the biochemical level could probably have a common ancestor

Phylogenetic Tree

is a branching diagram or “tree” showing the evolutionary relationships among various biological species or other entities - their phylogeny - based upon similarities and differences in their physical or genetic characteristics

Embryological Evidences

• embryo is an early stage of development in organisms
• the embryo of vertebrates are similar during the first stage of their embryonic development; and have several homologous structures that are not present when the organisms are adults

• Mutation
• Genetic drift
• Genetic flow
• Natural selection

Mechanisms of Evolution

Mutation

change in genetic material

Genetic Drift

change in frequency of gene variations in a population

Genetic Flow

migrating individuals transport genes

Natural Selection

• acts on variation “Survival of the Fittest”
• eliminates individuals that are less fit to the environment, allowing fitter individuals to survive and reproduce

Adaptation

• refers to the process by which organisms adjust and thrive in their environment
• it can also mean any change in or the acquisition of a trait that increases an organism’s chances of survival and reproduction

• Camouflage
• Mimicry

Two examples of Adaptation

Camouflage

some organisms hunt their prey or hide from predators by blending in with their environment

Mimicry

• a species resembles another species in term of behavior, appearance, sound or even scent
• Organisms mimic a more dangerous species so that they can scare or deter potential predators

Charles Robert Darwin

• was born in Shrewsbury, Shropshire, England
• was an English naturalist, geologist, and biologist
• published his theory of evolution with compelling evidence in his book “On the Origin of Species”
• died: April 19, 1882, Downe, Kent

February 12, 1809

When was Charles Robert Darwin born?

1859

When was Charles Darwin’s “On the Origin of Species” published?

Human Evolution

• it was presumed that a new species (human) developed because there was no longer need for swinging from trees
• walking upright on the ground required alterations in the foot for better speed and balance