Evolution and Origin of Species Flashcards
What evidence shows that life has changed over time?
Fossil records, comparative anatomy, embryology, molecular genetics, and biogeography all provide evidence of life’s changes over time.
Describe how the Earth changed and evolved over the last 4.6 billion years.
Over the last 4.6 billion years, the Earth has undergone significant changes and evolution. It has experienced the formation of continents, the development of diverse ecosystems, changes in climate and atmospheric composition, the emergence and extinction of various species, and the evolution of complex life forms.
What are fossils? What do fossil records show?
Fossils are the preserved remains or traces of organisms from past geological ages. Fossil records provide valuable evidence of the history of life on Earth. They show the existence of extinct species, the evolution of organisms over time, transitional forms that bridge the gaps between different species, and provide insights into ancient ecosystems and environmental conditions. Fossils help scientists understand the diversity, adaptation, and extinction of organisms, as well as the changes that have occurred on Earth over millions of years.
When looking at fossils in layers of rock, are fossils in deeper layers older
than fossils in layers not as deep?
Yes, fossils in deeper layers of rock are generally older than those in shallower layers. This principle is known as the law of superposition, which states that in undisturbed rock layers, the oldest rocks are located at the bottom, while the youngest rocks are found closer to the surface.
What does comparative morphology show?
Comparative morphology shows the similarities and differences in the form and structure of living organisms, providing evidence for evolutionary relationships, common ancestry, and adaptive changes over time.
What does geological evidence show?
Geological evidence shows the Earth’s history, past geological events, changes in climate and sea levels, tectonic plate movements, and the formation of landforms, providing insights into the planet’s geology, environments, and the evolution of life.
What does molecular biology evidence show?
Molecular biology evidence shows the genetic relationships and similarities between organisms, providing insights into evolutionary relationships, genetic inheritance, and the molecular basis of life processes.
Describe how the atmospheric oxygen levels changed over the last 4.6 billion years
Initially, the Earth’s atmosphere had very low oxygen levels, primarily consisting of gases like methane, ammonia, and carbon dioxide. However, around 2.5 billion years ago, a significant increase in oxygen levels occurred, known as the Great Oxygenation Event. This rise in oxygen was primarily a result of oxygen-producing photosynthetic organisms, such as cyanobacteria, that released oxygen as a byproduct of photosynthesis.
Microevolution
Microevolution refers to the small-scale genetic changes that occur within a population over time, leading to variations in traits from one generation to the next.
adaptive radiation
Adaptive radiation refers to the rapid diversification of a single ancestral species into multiple distinct species, each adapted to occupy different ecological niches or habitats. when one lineage may quickly give rise to many descendant species
macroevolution
Macroevolution refers to large-scale evolutionary changes that occur over long periods of time, resulting in the formation of new species, higher taxonomic groups, and the overall diversification of life forms. It involves the accumulation of microevolutionary changes and can lead to the emergence of new traits, evolutionary innovations, and the branching of lineages into distinct evolutionary trajectories.
mass extinctions
Mass extinctions refer to periods in Earth’s history when a significant number of species go extinct within a relatively short period of time. These events result in a rapid decline in biodiversity and can be caused by various factors such as major environmental changes, asteroid impacts, volcanic eruptions, or other catastrophic events.
What is Pangea? What happened to Pangea over time?
Pangea was a supercontinent that existed around 300 million years ago, during the late Paleozoic and early Mesozoic eras. It comprised the majority of Earth’s landmass, with all the continents grouped together as a single landmass.
Over time, Pangea began to break apart due to the process of plate tectonics. The supercontinent started to fragment into smaller landmasses, eventually leading to the formation of the continents we recognize today. This process, known as continental drift, involved the movement of tectonic plates, causing the continents to separate and drift apart. The breakup of Pangea resulted in the formation of new oceans, such as the Atlantic Ocean, and led to significant changes in global climate, biogeography, and the evolution of life on Earth.
What is the Cambrian explosion?
The Cambrian explosion refers to a relatively brief period in Earth’s history, approximately 541 million years ago, during which there was a rapid and remarkable diversification of complex multicellular life forms. It marked a significant milestone in the evolution of life, as it saw the emergence of a wide range of new body plans and the appearance of diverse organisms with hard shells, appendages, and other complex structures. The Cambrian explosion laid the foundation for the subsequent evolution and diversification of life on Earth.
What is the difference between an individual and a population?
An individual refers to a single organism, a distinct and separate living entity. It can be a single plant, animal, or any other living being.
A population, on the other hand, refers to a group of individuals of the same species that live in the same geographical area and have the potential to interbreed. A population consists of multiple individuals of the same species that can interact and reproduce with one another, sharing a common gene pool.
