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  2. Relative dating - Wikipedia

    en.wikipedia.org/wiki/Relative_dating

    Photo from Glen Canyon National Recreation Area, Utah. Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age (i.e., estimated age).

  3. Relative age effect - Wikipedia

    en.wikipedia.org/wiki/Relative_age_effect

    The distribution of births according to month in the general population. The term relative age effect (RAE), also known as birthdate effect or birth date effect, is used to describe a bias, evident in the upper echelons of youth sport [1] and academia, [2] where participation is higher amongst those born earlier in the relevant selection period (and lower for those born later in the selection ...

  4. Cross-cutting relationships - Wikipedia

    en.wikipedia.org/wiki/Cross-cutting_relationships

    Cross-cutting relationships can be used to determine the relative ages of rock strata and other structures. Explanations: A – folded rock strata cut by a thrust fault; B – large intrusion (cutting through A); C – erosional angular unconformity (cutting off A & B) on which rock strata were deposited; D – volcanic dike (cutting through A, B & C); E – even younger rock strata (overlying ...

  5. Fluorine absorption dating - Wikipedia

    en.wikipedia.org/wiki/Fluorine_absorption_dating

    However, since different sites have different levels of fluorine in the groundwater, fluorine absorption dating can only be used to determine the relative age of bones from the same site. It cannot give how old a bone actually is, only whether it is younger, older, or the same age as other bones from the same site. [1]

  6. Cheryl Tiegs is still a bombshell at 71: See her then and now

    www.aol.com/entertainment/cheryl-tiegs-still...

    Cheryl Tiegs, who shot to fame in 1978 after wearing a white fishnet swimsuit for Sports Illustrated, turns 72 in September 2019.

  7. Population pyramid - Wikipedia

    en.wikipedia.org/wiki/Population_pyramid

    World population pyramid from 1950 to projected in 2100 (UN, World Population Prospects 2017) A population pyramid (age structure diagram) or "age-sex pyramid" is a graphical illustration of the distribution of a population (typically that of a country or region of the world) by age groups and sex; it typically takes the shape of a pyramid when the population is growing. [1]

  8. Biostratigraphy - Wikipedia

    en.wikipedia.org/wiki/Biostratigraphy

    Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them. [1] The primary objective of biostratigraphy is correlation , demonstrating that a particular horizon in one geological section represents the same period of time as another ...

  9. Most recent common ancestor - Wikipedia

    en.wikipedia.org/wiki/Most_recent_common_ancestor

    The age of the human MRCA is unknown. It is no greater than the age of either the Y-MRCA or the mt-MRCA, estimated at 200,000 years. Unlike in pedigrees of individual humans or domesticated lineages where historical parentage is known, in the inference of relationships among species or higher groups of taxa ( systematics or phylogenetics ...