Ecology and Evolution

1. Ecology and Evolution Chapter 4

2. Ecosystems-everything is connected • All organisms are linked to each other in a complex web • Ecosystem – all the organisms living in an area together with their physical environment. Examples: Oak forest from example pg. 99, coral reefs

4. All ecosystems are connected – soil washes from mountains into a lake, birds migrate from North America to Mexico, pollen blows from one ecosystem to another

5. Components of an Ecosystem • Ecosystems need certain basic components to survive: energy, mineral nutrients, CO2, water, oxygen and living organisms • Energy from the sun • CO2 from animals to plants • Oxygen from plants to animals

6. Ecosystems are made up of both living and non-living things 1.)Biotic factors – all the living and once living parts of the ecosystem – plants, animals and dead organisms 2.)Abiotic factors – all the non-living parts of an ecosystem – air, water, rocks, sand, light and temperatures

7. Ecosystems are organized into levels 1.)Organisms – the individual – every organism is a member of a species – a group of organisms that can mate to produce fertile offspring • Ex. Humans – homo sapiens 2.)Populations – all the members of the same species that live in the same place at the same time • Its members breed with one another rather than members of other populations 3.)Communities – a group of various species (or populations) that live in the same place and interact with each other • Only made up of the biotic components • Ex. Pond communities include all the populations of plants, fish and insects that live in the pond

9. All living things in an ecosystem belong to one or more communities – a land community is characterized by the types of plants that are dominant. Ex. Pine forest attracts squirrels, etc.

10. Habitats • The place an organism lives. Ex. Howler monkey’s habitat is in a tropical rainforest. Cactus’s habitat Is a desert • Every habitat has specific biotic and abiotic factors that the organisms living there need to survive – if any factors change – habitat changes • Organisms tend to be very well suited to their natural habitat. Most animals and plants can’t survive for long away from their natural habitats because of the needs met by their habitat

12. Evolution • Organisms tend to be well suited to their habitats and what they do in their habitats because of evolution – a change in the genetic characteristics of a population from one generation to the next. • In 1859 Charles Darwin observed that organisms in a population differ slightly from each other in form, function and behavior which are usually hereditary – passed from parent to offspring

16. Darwin used the term natural selection – to describe why some individuals with certain traits are more likely to survive and reproduce • Ex. Lions with sharper claws can more easily catch and kill prey making them stronger and more likely to produce healthy offspring

19. Adaptation – an inherited trait that increases an organism’s chance of survival and reproduction in an environment

20. Coevolution – the process of 2 species evolving in response to long-term interactions with each other • Honeycreeper’s beak becomes long and curved to match the flowers evolved structures to protect its nectar

22. Evolution by Artificial Selection • People can control how domestic plants and animals reproduce and therefore evolve • Ex. Dogs and wolves • Artificial selection – selective breeding of organisms by humans for specific characteristics • Ex. Domestic plant crops, Chihuahuas

24. The Diversity of Living Things • Life on Earth is so diverse that it is classified into 6 kingdoms based on how they get their food, how many cells they have and if that cell has a nucleus or not or if it has cell walls or a membrane only • The 6 Kingdoms are: Archaebacteria, Eubacteria, Protist, Fungi, Plants and Animals

27. Archaebacteria • – single celled creatures which lack cell nuclei and often found in harsh environments. Ex. Methanogens and thermophiles

28. Thermophiles live in hot places like geysers or springs. Halophiles live in salty lakes. Some types live in high pressure or highly acidic places. Methanogens live in deep mud without oxygen. • Archae obtain energy from sulfur and ammonia. Chemical reactions with the substances pass electrons to each other, releasing energy for the cell's activities. Some are autotrophic, others

29. Eubacteria • single celled creatures and are common. Ex. Proteobacteria (found in soil and in animal intestines) and cyanobacteria or blue-green algae

31. Fungi • have cell walls – single or multi-celled, absorb food through their body. Ex. Mushrooms, yeast, mildew

32. Protists • most are single celled, most live in water. Ex. Amoebas, paramecia, euglena

34. Plants • multicellular, make own food – autotrophs through photosynthesis and have cell walls

36. Animals • – multicellular, no cell walls, ingest food – heterotrophs

38. Bacteria and the Environment • Play an important role in the environment • Some break down the remains and wastes of other organisms and then return nutrients to the soil • Some recycle nitrogen and phosphorous. Ex. Some convert N2 in the air into a form plants can use • Nitrogen is important because it is needed to build proteins and genetic material • Some allow organisms to extract nutrients from their food. Ex. E coli helps animals digest food and release vitamins but E coli and also cause food poisoning

39. Fungi • They decompose dead organisms however, they can cause diseases like ringworm, athlete’s foot. Some add flavor to food and yeasts produce gas that makes bread rise

40. Protists • Some are animal-like and others are plant-like • Most infamous is the plasmodium which causes malaria • Algae – autotrophic organisms and range in size from giant kelp to phytoplankton – the initial source of food in most ocean and freshwater ecosystems

41. Plants • Many-celled autotrophs – most have vascular tissue – a system of tubes that carry water and food through the plant • Lower Plants • Ancestors today like mosses have no vascular tissue and have to live in damp areas • Gymnosperms • Woody plants that produce seeds. Ex. Pine trees and other evergreens with needle-like leaves also called conifers – seeds are protected in cones • Angiosperms – most plants today • Flowering plants that produce seeds in fruit. The flower is the reproductive structure of the plant • Many angiosperms have large flowers that attract insects and/or birds to transport their pollen to other plants • Most of the food we eat comes from flowering plants. Ex. Oranges, lettuce, wheat, beans, etc.

42. Animals • Animals have to move in their environment to obtain food – have no cell walls so bodies are soft and flexible • 2 types: invertebrates and vertebrates

43. Invertebrates • Animals that lack backbones. Ex. Sponges, corals and other ocean filter-feeders, worms, mollusks (oysters), squids and insects • More insects exist on Earth than any other type of animal – they are adapted to most environments because of exoskeleton, quickly reproduce and most fly • Many insects and plants have coevolved – without pollinators we would not have a lot of the food that we eat • Some insects do transmit diseases – malaria, west nile, etc.

44. Vertebrates • Animals with backbones • 5 groups of vertebrates: 1.)Fish – first vertebrates 2.)Amphibians – return to water to lay eggs 3.)Reptiles – lay an almost waterproof egg allowing them to hatch on land 4.)Birds – lay hard shelled eggs and have feathers 5.)Mammals – have fur or hair and feed young milk produced by their bodies

45. Energy Flow in Ecosystems • The ultimate source of energy for almost all organisms is the Sun

46. Life depends on the Sun • Energy from the sun enters an ecosystem when a plant uses sunlight to make sugar molecules in a process called photosynthesis – plants, algae and some bacteria capture solar energy which starts a series of chemical reactions that require CO2 and water and then produce carbohydrates. • Other organisms consume these carbohydrates and use the energy stored in them. When animals eat plants, some energy is transferred from the plant to the animal. The plant is the producer – an organism that makes its own food – also known as autotrophs. The animal is the consumer – an organism that gets its energy by eating other organisms – also known as heterotrophs

47. An exception to the rule: Deep-ocean Ecosystems • The bottom of the ocean is teaming with life with large communities of organisms living near thermal vents. They exist in total darkness, where photosynthesis does not occur. • Bacteria that feed on hydrogen sulfide make their own food and serve as producers – other underwater organisms eat the bacteria which support a thriving ecosystem

49. Types of Consumers in an Ecosystem • Consumers that eat only producers are called herbivores. Ex. Cows • Consumers that eat other consumers only are called carnivores. Ex. Lions • Consumers that eat both plants and animals are called omnivores. Ex. Humans • Consumers that get their food by breaking down dead organisms are called decomposers. Ex. Bacteria and fungi – they return nutrients in rotting material to the soil, water, and air