ISB201 Evolution Symbiotic Relationships Spring 2024 Quiz How does antibiotic resistance develop in a population of bacteria Try this first How has the tuskless trait in developed in a population of African elephants Chunk it out 1 Explain the process for how the tuskless trait emerged in a population of African elephants 2 Demonstrate your understanding of Natural Selection and explain how one elephant being born without tusks has turned into appx 20 of the elephant population having the trait of no tusks 3 What changed with the current condition that contributed to the tuskless trait increasing over time QUIZ How does antibiotic resistance develop in a population of bacteria Now answer this question by swapping out elephants with bacteria tuskless with antibiotic resistance and poachers with antibiotic Today s Objectives Topics Co evolution Convergent Evolution Symbiosis Mutualism Commensalism Parasitism Concept Can I explain the process of how co evolved relationships develop Convergent Evolution Co Evolution How do these two terms concepts provide supporting evidence for Natural Selection Evolution To answer this question you will need to be able to define each provide examples and apply these concepts to what you learned about Natural Selection Evolution Convergent Evolution The process where unrelated organisms develop similar adaptations best suited for living in similar environments or obtaining energy bird mammal fish Convergent Evolution These species developed similar traits to access food energy Long claws for digging Long snouts for accessing food Long sticky tongues for gathering food Co Evolution The process whereby the evolution of one species drives the evolution of another Co Evolution Insects and Plants are highly co evolved Hammer Orchid and Hammer Orchid Wasp https youtu be 6yLnKfhmUzg Charles Darwin received an orchid specimen from Madagascar in 1862 good heavens what insect can suck it 20 years later the giant hawkmoth with a foot long tongue was discovered in Madagascar Co evolution or Convergent Foot long nectar spur with nectar only at very bottom Humans today have 3 species of lice Head lice body lice and pubic lice Why 3 different species and where did they come from The species acquired from the chimpanzee has evolved into two species on humans the head louse and body louse Can you explain the process Where is Co evolution demonstrated 1 species pubic lice came from the Gorilla louse 1 species from the chimpanzee Body Lice Head Lice Pubic Lice Head Lice Adults live about 1 month Females produce about 10 eggs which are laid in the hair nits Feed on human blood and tissues Lives entirely on the human They die after 24hrs off humans Body Lice Adults live about 1 month Females produce about 10 eggs which are laid on clothes or bedding Feed on human blood and tissues Lives off human but returns to feed Can survive 1 month off the human NOVA Lice and Human Evolution http www pbs org wgbh nova evolution lice html Understanding the evolution of human lice can give us information about the evolution of our past In this video they explain the concept of a Molecular Clock which looks at the rate genetic mutations occur and can help explain when species split from a common ancestor Symbiotic Relationships Symbiosis Symbiotic Relationships Two different species that live together either temporarily or prolonged where at least one organism benefits Symbiotic relationships are There are three types of symbiotic relationships 1 Mutualism 2 Commensalism 3 Parasitism Parasites Parasitoids of co evolution considered examples Mutualism Both organisms The Bullhorn Acacia Tree and Acacia Ant benefit The Acacia Tree benefits by receiving protection from herbivores both insects larger animals and ants clear the bases of trees to reduce competition for nutrients with other plants The ants benefit by receiving housing and nutrients food bribes directly from the plant Beltian bodies are structures produced by the acacia which are high in lipids sugars and proteins Ants receive nutrients from these structures The Acacia still needs pollinators for their reproduction which is problematic if ants are around protecting the trees When acacias flower and produce pollen there is a chemical change to the food that repels the ants This is still considered mutualism because in the bigger picture the ants are still benefiting from the relationship How did this relationship evolve Genetic variability possibly mutations Natural selection leading to adaptation Leading to evolution The mechanisms are the same whether we are talking about smaller elephant tusks antibiotic resistance or symbiosis Mutualism Gut Symbionts How do both benefit How do humans acquire their gut symbionts Commensalism 0 One benefits the other does not but is also not harmed Egrets Large Animals Egrets follow the herds and pick off insects as the animals move through brush or from their feces Parasitism One benefits the other is harmed Parasites are organisms that are harmful to another organism but do not kill the host Parasitoids are parasites that ultimately kill the host Are crab lice PARASITE OR PARASITOID Parasitism One benefits the other is harmed There are several species of parasitoid wasps that lay eggs on or within the larvae of another insect and eventually kill the host How can we use this knowledge to our advantage Pest Control One benefits the Parasitism other is harmed Cordyceps fungus infect a host insects other arthropods killing it and sprout stems that release spores into the air infecting other hosts There are thousands or Cordyceps species and each tends to attack a specific host specie Cordyceps attack of the killer fungi https youtu be XuKjBIBBAL8 C exigua extracts blood through the claws on its front causing the fishes tongue to atrophy from lack of blood The organism then replaces the fish s tongue by attaching its own body to the muscles of the tongue stub The fish is able to use the organism just like a normal tongue It appears that the organism does not cause any other damage to the host fish Once C exigua replaces the tongue some feed on the host s blood and many others feed on fish mucus This is the only known case of an organism functionally replacing a host organ When a host fish dies C exigua will detach itself from the tongue stub after some time leave the fish s mouth cavity and can then be seen clinging to its head or body externally It is not fully known what then happens to the