SPECIATION AND EXTINCTION - environmental biotechnology

This presentation examines the processes of speciation and extinction, discussing how they shape biodiversity and influence evolutionary patterns over time.

1. SPECIATION AND EXTINCTION SUBMITTED BY HARIPRIYA U VARMA 1 ST MSC BIOTECHNOLOGY NEHRU ARTS AND SCIENCE COLLEGE COIMBATORE

2. CONTENTS INTRODUCTION DEFINITION AND TYPES OF SPECIATION STEPS OF SPECIATION HOW DOES SPECIATION OCCURS? FACTORS AFFECTING SPECIATION

3. INTRODUCTION Group of organisms whose members has the potential to interbreed in nature and produce viable, fertile offspring or smallest group of organisms that share common ancestor are known as SPECIES. Development of new species through a variety of factors are called SPECIATION . Species got extinct when all the members die are called EXTINCTION

4. SPECIATION Speciation is the process of formation of new species from existing populations . It is also an evolutionary process of formation of new and distinct species. Rate of speciation depends on generation time, environmental conditions etc SPECIATION ALLOPATRIC SPECIATION PARAPATRIC SPECIATION PERIPATRIC SPECIATION SYMPATRIC SPECIATION

5. ALLOPATRIC SPECIATION Allopatric speciation is a type of speciation caused by geographic isolation . In this , the population is separated by a physical barrier. It is also referred to as geographic speciation, vicariant speciation. Example :- Northern spotted owl Mexican spotted owl Pic 1

6. PARAPATRIC SPECIATION Parapatric speciation is a type of speciation that are not formed by any physical barrier. Instead they are beside each other. This occurs by an extreme change in habitat. Individuals in these areas can interbreed, they develop different characteristics and lifestyle. Example:- Ephedra California Ephedra trifura

7. PERIPATRIC SPECIATION Peripatric speciation is a type of speciation that new species are formed from an isolated peripheral population. The population are prevented from exchanging genes and it is difficult to distinguish between them.

8. SYMPATRIC SPECIATION Sympatric speciation is a type of speciation that the evolution of new species from the surviving ancestral species in which both the species continue to live in same geographical region. Less common than allopatric speciation. This happens when gene flow is diminished by :- Polyploidy Habitat differentiation Sexual selection

9. STEPS OF SPECIATION - FLOWCHART

10. HOW DOES SPECIATION OCCURS? Gradualism- One species gradually transforming into another through a series of intermediate forms. Punctuated Equilibrium- Relatively brief bursts of rapid evolution interrupting long periods of little changes.

11. GRADUALISM AND PUNCTUATED EQUILIBRIUM

12. Adaptation of an organism that enables them to spread successfully or radiate into other environments. Adaptive radiation phenomenon was first observed by CHARLES DARWIN when he went to Galapagoes island. He observed that there were finches with different types of beaks. He concluded that all these finches radiated on the same island from a single ancestor finch.

13. FACTORS AFFECTING SPECIATION NATURAL SELECTION Process in nature through which living organisms adapt and change in response to an environmental conditions. GENETIC DRIFT Evolutionary change in allelic frequency of a population as a matter of change. BOTTLENECK EFFECT- Phenomenon in which a population reduced in size due to natural disasters, habitat loss, or overhunting. FOUNDER EFFECT- When small group splits off from the main population to found a colony. MIGRATION Transfer of individuals from one population to another population CHROMOSOMAL MUTATION Mutation involving a long segment of DNA which involves insertions, deletions, inversions, etc.

14. NATURAL SELECTION

15. EXTINCTION Extinction is the process of evolution that leads to the disappearance of a population or species. Over 99% of all species that once lived on earth, amounting to over five billion species are estimated to be extinct. This could happen naturally due to a change in the climate or because of human activities like overhunting or the destruction of habitat.

16. REFERENCE https://byjus.com/biology/speciation-evolution-factors/ https://www.slideshare.net/CandelaContent/13-speciation-chapter-13 https://www.britannica.com/science/speciation

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