{"doi":"10.5962/bhl.title.4547","title":"Genetic variations in relation to evolution; a critical inquiry into the observed types of inherited variation, in relation to evolutionary change, by H.S. Jennings ...","abstract":null,"journal":null,"year":1935,"id":616228,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1588668,"name":"H. S. Jennings","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Genetic variations in relation to evolution; a critical inquiry into the observed types of inherited variation, in relation to evolutionary change, by H.S. Jennings ...","abstract":"VARIATIONSnow see evolution occurring, as it sees inheritance occurring ?Are the known types of genetic variation adequate to bring about the salient features of organic evolution ?These are the questions with which we wish to deal.What are the salient features of organic evolution ?If we could watch the procession of living things from the beginning of life on the earth, what kinds of changes would we see?We can I believe list the main types of change under five heads:1. First, evolution is transformism.Organisms do not remain constant, but slowly change with the passage of time, as a developing child changes with the passage of time.2. Second, evolution is diversification.Organisms trans- form, not in one direction only, but in many directions.From an early simple situation is produced that which we now see about us: great numbers of animals and plants that are di- verse in many ways.3. Third, evolution brings about adaptation.Organisms develop structures and functions that tend to keep them in existence; to ward off dangers in a varied and changing world, and to obtain conditions favorable for their internal processes.Different organisms become adapted to different conditions.Otherwise expressed, evolution produces struc- tures and functions that bring about ends, of the sort that in human beings become the object of conscious purpose.And evolution produces, in man at least, some organisms whose behavior is consciously purposive.But, what is also important, there are produced, too, organ- isms that are not adaptive; organisms that fail to develop or to survive under the conditions of existence; a fact to which we shall have to recur.Adaptation is produced in evolution, but is not universal in the products of evolution.4. Fourth, progressiveness is a salient feature of evolution.Organisms were at first simple; in later ages some of these have transformed into complex highly differentiated animals and plants.From blobs of jelly-like material, responding inadequately to a few of the forces of nature, have developed organisms with elaborate sense organs and organs of response; creatures whose behavior is minutely and ade- quately correlated with processes in the surrounding world.But progressiveness, like adaptation, is not a universal feature of evolution.Highly developed organisms may de- generate into parasites, and many organisms still exist that have not developed beyond the lower grades of the organic scale.Whatever brings about evolution must be able to pro- duce progress; but it may produce also its opposite.5. Fifth and finally, as to the method of progress when prog- ress occurs, we must accept as a fact I believe the reports of students of progressive evolutionary series among fossil organ- isms such as are known in the development of the horse or the elephants.They report that progress in such series is continuous, gradual, by slight changes, not by sudden leaps.Continuity, not discontinuity, is the characteristic of such progressive series. enetic variations, to be adequate to the production of evolution, must then be of a sort to produce these five salient features: transformism, diversification, adaptation, progres- siveness and continuity.And now, certain points as to the nature of genetic varia- tions.In order that variations shall play a part in evolution, they must be inherited ; they must affect, not single individ- uals only but their descendants, becoming thus characteristics of a race or species.Only such can be called genetic variations. 1","is_dataset_classified":null,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"19767382","pmcid":null,"openalex_id":"https://openalex.org/W617584249","authors":[],"funders":[],"total_grants":0,"fwci":0.0,"citation_percentile":0.0134584,"influential_citations":0,"citation_trend":[{"year":2018,"count":1}],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://www.biodiversitylibrary.org/itempdf/23488","host_type":"repository"},{"url":"https://www.biodiversitylibrary.org/item/23488","host_type":"repository"},{"url":"https://www.biodiversitylibrary.org/bibliography/4547","host_type":"repository"},{"url":"http://ci.nii.ac.jp/ncid/BA08396565","host_type":"journal"}],"fields_of_study":["Evolution and Science Education"],"mesh_terms":[],"keywords":["Relation (database)","Variation (astronomy)","Evolutionary biology","Genetic variation","Epistemology","Biology","Philosophy","Genetics","Computer science","Data mining","Gene"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-02T22:20:12.389235Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}