Fossils and Sedimentary Rocks

Fossils and Sedimentary Rocks

• Fossils are preserved remnants of once living organisms trapped in rocks, tar pits, frozen in ice, or embedded in amber.
• Examples of fossils include bone fossils, shell fossils, and seed or pollen grain fossils.
• Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms and often have distinctive layering or bedding.

Paleontology and Geology

• A paleontologist is a specialist in the study of the forms of life existing in prehistoric or geologic times.
• Paleontologists study the history of life on Earth through the fossil record.

Relative and Absolute Dating

• Relative dating is the process of determining if one rock or geologic event is older or younger than another, without knowing their specific ages.
• Geologists use relative dating by identifying the position of rocks with respect to one another; rocks in deeper strata are generally older.
• Absolute dating is the process of determining the specific age of rocks by measuring the degree of decay of certain radioisotopes contained in the rock.

Radioactive Isotopes and Strata

• Radioactive isotopes are atoms that contain an unstable combination of neutrons and protons or excess energy in the nucleus.
• Strata refers to a layer or a series of layers of rock in the ground.
• Stable isotopes can be found in living rocks, and the presence of many stable isotopes indicates the age of the rock.

Embryology

• Embryology is the study of the early stages of development in humans and other animals or plants.
• An embryo is an organism in its initial phase of development.
• The notochord serves as a source of midline signals that pattern surrounding tissues and is a major skeletal element of the developing embryo.
• Pharyngeal pouches produce tissues necessary for hearing development, calcium homeostasis, and adequate immune response.

Anatomical Evidences

• Anatomical evidences support the idea of "descent from a common ancestor."
• The more body structures that two species have in common, the more closely they are related.
• There are three types of anatomical structures: homologous, analogous, and vestigial.

Anatomical Structures

• Homologous structures are similar structures in different species, regardless of their functions.
• Analogous structures are different in appearance but have similar functions.
• Vestigial structures are anatomical features that have lost their original function.

Biochemical Evidences

• Living organisms share numerous related biochemical molecules, such as DNA, ATP, amino acids, and enzymes.
• There are two major types of biochemical molecules: DNA/nucleic acids and proteins.
• DNA is found in chromosomes and is used to build and repair body parts.
• Proteins are molecules used to build up and repair body parts.

Phylogenetic Tree

• A phylogenetic tree is a diagram that represents evolutionary relationships among organisms.
• The pattern of branching in a phylogenetic tree reflects how species or other groups evolved from a series of common ancestors.
• In trees, two species are more related if they have a more recent common ancestor and less related if they have a less recent common ancestor.

Test your knowledge of fossils, how they're formed, and sedimentary rocks. Learn about the different types of fossils, such as bone and shell fossils, and the characteristics of sedimentary rocks. A great quiz for paleontology enthusiasts!