diff --git a/package-lock.json b/package-lock.json
index d7a2c09..b5cdca7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14558,9 +14558,9 @@
       "dev": true
     },
     "topola": {
-      "version": "2.5.1",
-      "resolved": "https://registry.npmjs.org/topola/-/topola-2.5.1.tgz",
-      "integrity": "sha512-g1hDeT0X4HHg/p1/Wr/fgUceN9JlP6LC1rIJkfP7lPwWVZcplzfdCDzuyIKPfkrUsE5OZAhw3LoPu6xKv1u/dg==",
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/topola/-/topola-3.0.0.tgz",
+      "integrity": "sha512-taln1nxS819MpxtIwqCjW47VljOT9HBhpaxtjSqVEKPBzXV8/zLIemF2NkIMSuH+7jnKJllpXAc1FAseBC0cfA==",
       "requires": {
         "array-flat-polyfill": "^1.0.1",
         "d3": "^5.4.0",
diff --git a/package.json b/package.json
index cc4c565..f0b3dd0 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
     "react-router-dom": "^4.3.1",
     "semantic-ui-css": "^2.4.1",
     "semantic-ui-react": "^0.84.0",
-    "topola": "^2.5.1"
+    "topola": "^3.0.0"
   },
   "devDependencies": {
     "@types/array.prototype.flatmap": "^1.2.0",
diff --git a/src/app.tsx b/src/app.tsx
index 9d1d46f..1081ea3 100644
--- a/src/app.tsx
+++ b/src/app.tsx
@@ -74,6 +74,16 @@ interface GedcomMessage extends EmbeddedMessage {
   gedcom?: string;
 }
 
+/** Returs true if the changes object has values that are different than those in state. */
+function hasUpdatedValues<T>(state: T, changes: Partial<T> | undefined) {
+  if (!changes) {
+    return false;
+  }
+  return Object.entries(changes).some(
+    ([key, value]) => value !== undefined && state[key] !== value,
+  );
+}
+
 interface State {
   /** Loaded data. */
   data?: TopolaData;
@@ -99,6 +109,7 @@ interface State {
   showErrorPopup: boolean;
   /** True if data is loaded from WikiTree. */
   wikiTreeSource: boolean;
+  loadingMore?: boolean;
 }
 
 export class App extends React.Component<RouteComponentProps, {}> {
@@ -135,18 +146,18 @@ export class App extends React.Component<RouteComponentProps, {}> {
   }
 
   /** Sets the state with a new individual selection and chart type. */
-  private updateDisplay(selection: IndiInfo, chartType?: ChartType) {
+  private updateDisplay(
+    selection: IndiInfo,
+    otherStateChanges?: Partial<State>,
+  ) {
     if (
       !this.state.selection ||
       this.state.selection.id !== selection.id ||
       this.state.selection!.generation !== selection.generation ||
-      (chartType !== undefined && chartType !== this.state.chartType)
+      hasUpdatedValues(this.state, otherStateChanges)
     ) {
       this.setState(
-        Object.assign({}, this.state, {
-          selection,
-          chartType: chartType !== undefined ? chartType : this.state.chartType,
-        }),
+        Object.assign({}, this.state, {selection}, otherStateChanges),
       );
     }
   }
@@ -308,7 +319,31 @@ export class App extends React.Component<RouteComponentProps, {}> {
         indi,
         generation,
       );
-      this.updateDisplay(selection, chartType);
+      const loadMoreFromWikitree =
+        source === 'wikitree' &&
+        (!this.state.selection || this.state.selection.id !== selection.id);
+      this.updateDisplay(selection, {
+        chartType,
+        loadingMore: loadMoreFromWikitree || undefined,
+      });
+      if (loadMoreFromWikitree) {
+        const data = await loadWikiTree(indi!);
+        this.setState(
+          Object.assign({}, this.state, {
+            data,
+            hash,
+            selection: getSelection(data.chartData, indi, generation),
+            error: undefined,
+            loading: false,
+            url,
+            showSidePanel,
+            standalone,
+            chartType,
+            wikiTreeSource: source === 'wikitree',
+            loadingMore: false,
+          }),
+        );
+      }
     }
   }
 
@@ -399,6 +434,9 @@ export class App extends React.Component<RouteComponentProps, {}> {
             message={this.state.error}
             onDismiss={this.onDismissErrorPopup}
           />
+          {this.state.loadingMore ? (
+            <Loader active inline size="small" />
+          ) : null}
           <Chart
             data={this.state.data.chartData}
             selection={this.state.selection}
diff --git a/src/chart.tsx b/src/chart.tsx
index ae8f667..d31ef9f 100644
--- a/src/chart.tsx
+++ b/src/chart.tsx
@@ -164,6 +164,8 @@ export class Chart extends React.PureComponent<ChartProps, {}> {
         updateSvgSize: false,
         locale: this.context.intl.locale,
       });
+    } else {
+      this.chart!.setData(this.props.data);
     }
     const chartInfo = this.chart!.render({
       startIndi: this.props.selection.id,
@@ -227,9 +229,7 @@ export class Chart extends React.PureComponent<ChartProps, {}> {
   }
 
   componentDidUpdate(prevProps: ChartProps) {
-    const initialRender =
-      this.props.data !== prevProps.data ||
-      this.props.chartType !== prevProps.chartType;
+    const initialRender = this.props.chartType !== prevProps.chartType;
     this.renderChart({initialRender});
   }
 
diff --git a/src/wikitree.ts b/src/wikitree.ts
index 1c75c46..2b5aeb7 100644
--- a/src/wikitree.ts
+++ b/src/wikitree.ts
@@ -63,8 +63,16 @@ async function wikiTreeGet(request: WikiTreeRequest, handleCors: boolean) {
   return JSON.parse(responseBody);
 }
 
-/** Retrieves ancestors from WikiTree for the given person ID. */
+/**
+ * Retrieves ancestors from WikiTree for the given person ID.
+ * Uses sessionStorage for caching responses.
+ */
 async function getAncestors(key: string, handleCors: boolean) {
+  const cacheKey = `wikitree:ancestors:${key}`;
+  const cachedData = sessionStorage.getItem(cacheKey);
+  if (cachedData) {
+    return JSON.parse(cachedData);
+  }
   const response = await wikiTreeGet(
     {
       action: 'getAncestors',
@@ -73,21 +81,48 @@ async function getAncestors(key: string, handleCors: boolean) {
     },
     handleCors,
   );
-  return response[0].ancestors as Person[];
+  const result = response[0].ancestors as Person[];
+  sessionStorage.setItem(cacheKey, JSON.stringify(result));
+  return result;
 }
 
-/** Retrieves relatives from WikiTree for the given array of person IDs. */
+/**
+ * Retrieves relatives from WikiTree for the given array of person IDs.
+ * Uses sessionStorage for caching responses.
+ */
 async function getRelatives(keys: string[], handleCors: boolean) {
+  const result: Person[] = [];
+  const keysToFetch: string[] = [];
+  keys.forEach((key) => {
+    const cachedData = sessionStorage.getItem(`wikitree:relatives:${key}`);
+    if (cachedData) {
+      result.push(JSON.parse(cachedData));
+    } else {
+      keysToFetch.push(key);
+    }
+  });
+  if (keysToFetch.length === 0) {
+    return result;
+  }
   const response = await wikiTreeGet(
     {
       action: 'getRelatives',
-      keys: keys.join(','),
+      keys: keysToFetch.join(','),
       getChildren: true,
       getSpouses: true,
     },
     handleCors,
   );
-  return response[0].items.map((x: {person: Person}) => x.person) as Person[];
+  const fetchedResults = response[0].items.map(
+    (x: {person: Person}) => x.person,
+  ) as Person[];
+  fetchedResults.forEach((person) => {
+    sessionStorage.setItem(
+      `wikitree:relatives:${person.Name}`,
+      JSON.stringify(person),
+    );
+  });
+  return result.concat(fetchedResults);
 }
 
 /**