Pancake Evolution: A Novel & Engaging Illustration of Natural Selection

2019 ◽  
Vol 81 (2) ◽  
pp. 110-114 ◽  
Author(s):  
D. Andrew Crain ◽  
Matthew Hale
Keyword(s):  
Genetic Diversity ◽  
Natural Selection ◽  
Second Generation ◽  
Population Change ◽  
Allelic Variation ◽  
Postsecondary Students ◽  
Change Over Time ◽  
Changing Environments ◽  
Over Time ◽  
Made In

Understanding the theory of natural selection is crucial for any student of biology, but many secondary and postsecondary students struggle with the concepts. We present a novel, engaging exercise to illustrate natural selection through making pancakes. After students make pancakes (representing offspring) with various ingredients (illustrating genetic diversity and allelic variation), other students (representing the environment) judge the pancakes on the basis of taste. Only the highest-ranking pancakes are made in a second generation (illustrating population change over time), and new ingredients are added. After several generations of pancakes, with each generation exposed to ever-changing “environments,” students understand the fundamental concepts associated with the theory of natural selection.

Comparing rates between and within populations

2018 ◽  
pp. 19-27
Author(s):  
Alan J. Silman ◽  
Gary J. Macfarlane ◽  
Tatiana Macfarlane
Keyword(s):  
Population Change ◽  
Mortality Rates ◽  
Change Over Time ◽  
Time Points ◽  
Disease Rates ◽  
Over Time

In comparing rates between populations, it is important that one is comparing ‘like with like’. One population may be considerably older than a population to which it is compared and therefore it would not be surprising that mortality rates were higher. Instead it is more useful to make comparisons taking account of differences in characteristics such as age or gender. The same considerations apply to examining disease rates over time in a given population. If the characteristics of the population change over time (e.g. the population gets older), this needs to be considered. To formulate hypotheses, the rate of a disease under study in a population may be compared with the rate in other populations, or in the same population at difierent time points. If the rates vary significantly between populations or are changing within a population, then this provides impetus for investigating the reasons underlying these differences or changes.

World Population Change over Time

2012 ◽  
pp. 265-285
Author(s):  
Dudley L. Jr. Poston ◽  
Leon F. Bouvier
Keyword(s):  
Population Change ◽  
World Population ◽  
Change Over Time ◽  
Over Time

scholarly journals Analgesic use in a Norwegian general population: change over time and high-risk use - The Tromsø Study

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Per-Jostein Samuelsen ◽  
Lars Slørdal ◽  
Ulla Dorte Mathisen ◽  
Anne Elise Eggen
Keyword(s):  
High Risk ◽  
General Population ◽  
Population Change ◽  
Change Over Time ◽  
Analgesic Use ◽  
Over Time

The Macro-dynamics of Partisan Advantage

2018 ◽  
Vol 72 (2) ◽  
pp. 450-459
Author(s):  
Logan Dancey ◽  
Matthew Tarpey ◽  
Jonathan Woon
Keyword(s):  
Strong Relationship ◽  
Presidential Approval ◽  
Agenda Control ◽  
Change Over Time ◽  
The Common ◽  
Over Time ◽  
Made In

How do party reputations change over time? We construct a measure of the common movement in the parties’ perceived policy handling abilities for the period 1980 to 2016 and investigate its relationship with the public’s evaluation of Congress and the president. In contrast to key claims made in theories of congressional parties, we find an inconsistent relationship between evaluations of Congress and party reputations and find no evidence that successful agenda control enhances the majority party’s reputation. Instead, our analysis shows a strong relationship between party reputations and presidential approval, reaffirming the central role the president plays in shaping party reputations.

scholarly journals Online Learning in Changing Environments

2020 ◽  
Author(s):  
Lijun Zhang
Keyword(s):  
Online Learning ◽  
Performance Measures ◽  
Online Algorithms ◽  
Change Over Time ◽  
Changing Environments ◽  
Recent Developments ◽  
Novel Algorithms ◽  
The Relationship ◽  
Over Time

The usual goal of online learning is to minimize the regret, which measures the performance of online learner against a fixed comparator. However, it is not suitable for changing environments in which the best decision may change over time. To address this limitation, new performance measures, including dynamic regret and adaptive regret have been proposed to guide the design of online algorithms. In dynamic regret, the learner is compared with a sequence of comparators, and in adaptive regret, the learner is required to minimize the regret over every interval. In this paper, we will review the recent developments in this area, and highlight our contributions. Specifically, we have proposed novel algorithms to minimize the dynamic regret and adaptive regret, and investigated the relationship between them.

scholarly journals How Darwinian is cultural evolution?

2014 ◽  
Vol 369 (1642) ◽  
pp. 20130368 ◽  
Author(s):  
Nicolas Claidière ◽  
Thomas C. Scott-Phillips ◽  
Dan Sperber
Keyword(s):  
Cultural Evolution ◽  
Cultural Transmission ◽  
Population Thinking ◽  
Change Over Time ◽  
Darwinian Selection ◽  
Adequate Understanding ◽  
Different Types ◽  
Substantial Progress ◽  
Over Time ◽  
Made In

Darwin-inspired population thinking suggests approaching culture as a population of items of different types, whose relative frequencies may change over time. Three nested subtypes of populational models can be distinguished: evolutionary, selectional and replicative. Substantial progress has been made in the study of cultural evolution by modelling it within the selectional frame. This progress has involved idealizing away from phenomena that may be critical to an adequate understanding of culture and cultural evolution, particularly the constructive aspect of the mechanisms of cultural transmission. Taking these aspects into account, we describe cultural evolution in terms of cultural attraction , which is populational and evolutionary, but only selectional under certain circumstances. As such, in order to model cultural evolution, we must not simply adjust existing replicative or selectional models but we should rather generalize them, so that, just as replicator-based selection is one form that Darwinian selection can take, selection itself is one of several different forms that attraction can take. We present an elementary formalization of the idea of cultural attraction.

scholarly journals Erratum to: Analgesic use in a Norwegian general population: change over time and high-risk use - The Tromsø Study

2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Per-Jostein Samuelsen ◽  
Lars Slørdal ◽  
Ulla Dorte Mathisen ◽  
Anne Elise Eggen
Keyword(s):  
High Risk ◽  
General Population ◽  
Population Change ◽  
Change Over Time ◽  
Analgesic Use ◽  
Over Time
Sign in / Sign up

Export Citation Format

Share Document